This case requires us to determine whether threats of litigation between purely private parties in a non-antitrust setting are immunized from liability under the Noerr-Pennington doctrine or under the right to petition clause of the First Amendment. Because purely private threats do not constitute a petition to the government, we hold that they are not constitutionally protected.
Background
The facts are undisputed. In 1992, Cardtoons, L.C. (“Cardtoons”), an Oklahoma limited liability company, took steps to produce parody baseball trading cards which contained the images of major league baseball players. After the cards were designed, Cardtoons contracted with Champs Marketing, Inc. (“Champs”), an Ohio corporation, to print the cards for a set fee.
Major League Baseball Players Association (“MLBPA”) is the exclusive collective bargaining agent for all active major league baseball players and is responsible for enforcing the publicity rights of the players. In a June 18,1993 letter to Card-toons (“Cardtoons letter”), the MLBPA claimed that by producing and selling the cards, Cardtoons was “violat[ing] the valuable property rights of MLBPA and the players.” I R. at 8. The MLBPA threatened to “pursue its full legal remedies to enforce its rights” if Cardtoons did not immediately cease production of the cards. Id. at 9.
On the same date, the MLBPA also sent a similar cease and desist letter to Champs (the Champs letter). It is this letter that is the source of the present controversy. In pertinent part, it stated:
We understand that you have and are in the process of printing color drawings of active Major League baseball players in baseball trading cards for individuals associated with Cardtoons. This is to notify you that we believe that the activities of those individuals violate the valuable property rights of publicity of the MLBPA and the players themselves. Further, we believe that by printing the baseball trading cards at the request of *887Cardtoons, you are participating in Cardtoons’ illegal activities.
Accordingly, we request that you immediately cease and desist-the printing of baseball trading cards of active Major League baseball players at the request of Cardtoons or others who are not authorized to use the likeness of active Major League baseball players.
If I do not hear from, you immediately confirming that you will agree to this request, I will have no alternative but to take all necessary action to enforce the rights of the players and the MLBPA against infringement of their rights.
Id. at 10, 10A. Upon receiving the letter, Champs informed Cardtoons that it intended to stop printing the cards.
On June 22, 1993, Cardtoons filed suit in federal district court seeking a declaratory judgment that its cards did not violate MLBPA’s publicity rights and also seeking damages based on alleged tortious interference with the Champs contract. MLBPA moved to dismiss for lack of subject matter jurisdiction and filed counterclaims seeking declaratory and injunctive relief, as well as damages for violation of its publicity rights. The court bifurcated the proceedings to first resolve Cardtoons’ declaratory judgment request, finding that the damages issues were dependent upon the legality of the parody cards.
The district court initially adopted a magistrate judge’s recommendations and ruled in favor of the MLBPA. See Cardtoons, L.C. v. Major League Baseball Players Ass’n, 838 F.Supp. 1501 (N.D.Okla.1993). However, following the Supreme Court’s decision in Campbell v. Acuff-Rose Music, Inc., 510 U.S. 569, 114 S.Ct. 1164, 127 L.Ed.2d 500 (1994), the district court concluded that the parody cards were protected under the First Amendment. Accordingly, the court vacated its initial decision and entered judgment in favor of Cardtoons. See Cardtoons, L.C. v. Major League Baseball Players Ass’n, 868 F.Supp. 1266 (N.D.Okla.1994) (“Cardtoons I”). This court affirmed on appeal, determining that the cards were “an important form of entertainment and social commentary that deserve First Amendment protection.” Cardtoons, L.C. v. Major League Baseball Players Ass’n, 95 F.3d 959, 976 (10th Cir.1996) (“Cardtoons II ”).
Cardtoons returned to the district court to pursue its damages claims against the MLBPA. The court allowed Cardtoons to amend its complaint and assert new claims for prima facie tort, libel and negligence. All of Cardtoons’ claims stemmed from the allegations contained in the Champs letter. The district court concluded that the MLBPA was immune from liability under the Noerr-Pennington doctrine and entered summary judgment for MLBPA on all of Cardtoons’ claims. Cardtoons, L.C. v. Major League Baseball Players Ass’n, No. 93-C-576-E (N.D.Okla. Mar. 12, 1998) (“Cardtoons III”).
• On appeal, a panel of this court upheld the grant of summary judgment. Cardtoons, L.C. v. Major League Baseball Players Ass’n, 182 F.3d 1132 (10th Cir.1999) (“Cardtoons IV”). The panel majority determined that the Noerr-Pennington doctrine applies apart from its roots in antitrust. In determining whether immunity for writing the letters was appropriate, the panel majority focused on the two part test enunciated in Professional Real Estate Investors, Inc. v. Columbia Pictures, Inc., 508 U.S. 49, 60-61, 113 S.Ct. 1920, 123 L.Ed.2d 611 (1993) (“PRE”).
In critical part, the panel majority held that Noerr-Pennington immunity covered threats of -litigation as well as the actual litigation itself. “We adopt the legal and policy rationales that have informed other circuits’ extension of Noerr-Pennington immunity to prelitigation threats, and hold that whether, or not they are consummated, such threats enjoy the same level of protection from liability as litigation itself.” Cardtoons IV, 182 F.3d at 1137. The panel majority went on to hold that the MLBPA had probable cause to threaten *888the lawsuit against Champs, thus satisfying the PRE test. “Accordingly, the Champs letter enjoyed Noerr-Pennington immunity as a threat of litigation.” Card-toons IV, 182 F.3d at 1139.
In dissent, Judge Ebel questioned whether Noerr-Pennington immunity should be extended to cover purely private threats. Rather than apply the two-part PRE test designed for litigation, Judge Ebel espoused a three part test for threats of litigation. A party seeking Noerr-Pen-nington immunity must show that the threat was (1) made in good faith; (2) was objectively reasonable; and (3) was a “proximate prologue to actual or imminent litigation.” Cardtoons IV, 182 F.3d at 1142 (Ebel, J., dissenting).
Cardtoons sought rehearing en banc, arguing that the panel majority misapplied the Noerr-Pennington doctrine, and the case should be governed solely by the First Amendment right to petition. In particular, it pointed to the decisions in McDonald v. Smith, 472 U.S. 479, 105 S.Ct. 2787, 86 L.Ed.2d 384 (1985) and Martin v. City of Del City, 179 F.3d 882 (10th Cir.1999) as contrary to the panel opinion. We granted rehearing en banc. For the reasons stated below, we reverse the panel and remand.
I. Noerr-Pennington Immunity
The Noerr-Pennington doctrine was first recognized in two antitrust cases: Eastern R.R. Presidents Conference v. Noerr Motor Freight, Inc., 365 U.S. 127, 81 S.Ct. 523, 5 L.Ed.2d 464 (1961) and United Mine Workers v. Pennington, 381 U.S. 657, 85 S.Ct. 1585, 14 L.Ed.2d 626 (1965). The present case does not involve antitrust claims, and therefore, we must first address the applicability of Noerr-Pennington outside the antitrust context.1
Noerr involved an extensive publicity campaign by the railroad industry aimed at changing state law to place various restrictions on trucking in the long-distance freight business. The trucking industry brought suit in antitrust, alleging violations of §§ 1 and 2 of the Sherman Act. The Court held that the railroads were immune from suit because “the Sherman Act does not apply to the activities of the railroads at least insofar as those activities comprised mere solicitation of governmental action with respect to the passage and enforcement of laws.” Noerr, 365 U.S. at 138, 81 S.Ct. 523.2
This immunity was based upon two grounds. See City of Lafayette v. Louisiana Power & Light Co., 435 U.S. 389, 399, 98 S.Ct. 1123, 55 L.Ed.2d 364 (1978) (noting the “two correlative principles” on which Noerr immunity was established); see also California Motor Transport Co. v. Trucking Unlimited, 404 U.S. 508, 510, 92 S.Ct. 609, 30 L.Ed.2d 642 (1972). The first was a statutory interpretation of the Sherman Act.
To hold that the government retains the power to act in [a] representative capacity and yet hold, at the same time, that the people cannot freely inform the government of their wishes would impute to the Sherman Act a purpose to regulate, not business activity, but political activity, a purpose which would have no basis whatever in the legislative history of that Act.
Noerr, 365 U.S. at 137, 81 S.Ct. 523. The second basis for immunity was predicated on the First Amendment right to petition.
Secondly, and of at least equal significance, such a construction of the Sher*889man Act .would raise important constitutional questions. The right of petition is one of the freedoms protected by the Bill of Rights, and we cannot, of course, lightly impute to Congress an intent to invade these freedoms.
Id. at 137-38, 81 S.Ct. 523. The Court has referred to these two prongs as “[i]nter-preting the Sherman Act in the light of the First Amendment’s Petition Clause.” Federal Trade Comm’n v. Superior Ct. Trial Law. Ass’n, 493 U.S. 411, 424, 110 S.Ct. 768, 107 L.Ed.2d 851 (1990).
The logical dilemma in applying Noerr-Pennington outside of the antitrust context is that Noerr’s first rationale for immunity — an interpretation of the Sherman Act — is not present. Supreme Court precedent gives us scant guidance in resolving this issue. All of the cases in which the Supreme Court has applied Noerr-Pen-nington immunity as such have involved antitrust claims. See e.g. PRE, 508 U.S. at 52, 113 S.Ct. 1920; City of Columbia v. Omni Outdoor Advertising, 499 U.S. 365, 369, 111 S.Ct. 1344, 113 L.Ed.2d 382 (1991); Superior Ct. Trial Law. Ass’n, 493 U.S. at 422, 110 S.Ct. 768; Allied Tube & Conduit Corp. v. Indian Head, Inc., 486 U.S. 492, 497, 108 S.Ct. 1931, 100 L.Ed.2d 497 (1988); Pennington, 381 U.S. at 659, 85 S.Ct. 1585; Noerr, 365 U.S. at 129, 81 S.Ct. 523.
To the extent that Supreme Court precedent can be read to extend Noerr-Pen-nington outside of the antitrust context, it does so solely on the basis of the right to petition. See Bill Johnson’s Restaurants, Inc. v. NLRB, 461 U.S. 731, 742-43, 103 S.Ct. 2161, 76 L.Ed.2d 277 (1983) (immunizing employer’s law suit from NLRB injunction under the right to petition); NAACP v. Claiborne Hardware, 458 U.S. 886, 913-14, 102 S.Ct. 3409, 73 L.Ed.2d 1215 (1982) (granting First Amendment immunity to a nonviolent business boycott seeking to vindicate economic and equal rights). See also PRE, 508 U.S. at 59, 113 S.Ct. 1920 (noting that the Court has “in-vok[ed Noerr ] in other contexts” and has referenced it “by analogy”). But see Omni Outdoor Advertising, 499, U.S. at 384, 111 S.Ct. 1344 (granting Noerr immunity to federal antitrust claims but permitting liability under state law “trade libel” and other claims based on the same underlying conduct).
The circuits have followed suit, eliminating the Sherman Act rationale outside of antitrust and focusing solely on the petition clause. For instance, the Third Circuit in We, Inc. v. City of Philadelphia, 174 F.3d 322, 326-27 (3d Cir.1999) stated: “This court, along with other courts, has by analogy extended the Noerr-Penning-ton doctrine to offer protection to citizens’ petitioning activities in contexts outside the antitrust area as well.... [T]he purpose of Noerr-Pennington as applied in areas outside the antitrust field is the protection of the right to petition.” The Fifth Circuit has noted that “[ajlthough the Noerr-Pennington doctrine initially arose in the antitrust field, other circuits have expanded it to protect first amendment petitioning of the government from claims brought under federal and state laws.... ” Video Int’l Production, Inc. v. Wamer-Amex Cable Communications, Inc., 858 F.2d 1075, 1084 (5th Cir.1988).3
While we do not question the application of the right to petition outside of antitrust, it is a bit of a misnomer to refer to it as the Noerr-Pennington doctrine; a doctrine which was based on two rationales. In our view, it is more appropriate to refer to immunity as Noerr-Pennington immunity only when applied to antitrust claims.4 In all other contexts, *890including the present one, such immunity derives from the right to petition.
This distinction is not completely academic. Antitrust cases that grant Noerr-Pennington immunity do so based upon both the Sherman Act and the right to petition. These precedents, founded in part upon a construction of the Sherman Act, are not completely interchangeable with cases based solely upon the right to petition.
The Fifth Circuit antitrust decision in Coastal States Marketing, Inc. v. Hunt, 694 F.2d 1358 (5th Cir.1983) is a classic example of the difficulties which can arise if this distinction is not made. MLBPA relies heavily upon this case for the proposition that Noerr-Pennington immunity extends to prelitigation threats of suit. In Coastal States, the plaintiff argued that defendants’ threats to litigate could not be immunized under Noerr. “[B]ecause threats of litigation are not directed to a government, they do not fall within the rationale of petitioning immunity.” Coastal States, 694 F.2d at 1367. The Fifth Circuit rejected this argument.
Given that petitioning immunity protects joint litigation, it would be absurd to hold that it does not protect those acts reasonably and normally attendant upon effective litigation. The litigator should not be protected only when he strikes without warning. If litigation is in good faith, a token of that sincerity is a warning that it will be commenced and a possible effort to compromise the dispute.
Id.
If we were to refer to immunity based solely on the right to petition as Noerr-Pennington immunity, it would be very tempting to apply Coastal States in the present case. To do so, however, would be inappropriate. First, Coastal States rejected the right to petition as a basis for Noerr. “Noerr was based on a construction of the Sherman Act. It was not a first amendment decision.” Coastal States, 694 F.2d at 1364-65 (footnote omitted). Second, and even more instructive, the Fifth Circuit specifically noted that its use of the term “petitioning immunity” went beyond the guarantees of the petition clause. “We reject the notion that petitioning immunity extends only so far as the first amendment right to petition and then ends abruptly.” Id. at 1366.
*891Coastal States’ grant of immunity to prelitigation threats was not based on the right to petition and, therefore, does not inform our decision in the present non-antitrust case.5 This is not to intimate that right to petition principles can never be drawn from Noerr-Pennington antitrust eases. Rather, it is merely a precautionary distinction designed to avoid drawing constitutional principles from propositions founded upon statutory construction.
II. Right to Petition
We must now determine whether prelitigation threats communicated solely between private parties are afforded immunity from suit by the right to petition guaranteed by the First Amendment. We hold that they are not.
The First Amendment states: “Congress shall make no law respecting ... the right of the people ... to petition the Government for a redress of grievances.” The right to petition “is implicit in ‘[t]he very idea of government, republican in form.’ ” McDonald v. Smith, 472 U.S. 479, 482, 105 S.Ct. 2787, 86 L.Ed.2d 384 (1985) (quoting United States v. Cruikshank, 92 U.S. 542, 552, 23 L.Ed. 588 (1876)). “Certainly the right to petition extends to all departments of the Government. The right of access to the courts is indeed but one aspect of the right of petition.” California Motor, 404 U.S. at 510, 92 S.Ct. 609; see also City of Del City, 179 F.3d at 887.
However, the right to petition is not an absolute protection from liability. In McDonald, petitioner wrote a letter to President Reagan accusing respondent of fraud, blackmail, extortion, and the violation of various individuals’ civil rights. Respondent was being considered for the position of United States Attorney but was not appointed. He brought a libel suit against petitioner, who claimed that the right to petition gave him absolute immunity in his statements to the president. The Supreme Court disagreed.
To accept petitioner’s claim of absolute immunity would elevate the Petition Clause to special First Amendment status. The Petition Clause, however, was inspired by the same ideals of liberty and democracy that gave us the freedoms to speak, publish, and assemble. These First Amendment rights are inseparable, and there is no sound basis for granting greater constitutional protection to statements made in a petition to the President than other First Amendment expressions.
McDonald, 472 U.S. at 485, 105 S.Ct. 2787 (citations omitted). The Court affirmed the lower courts in allowing the libel action to proceed. “The right to petition is guaranteed; the right to commit libel with impunity is not.” Id.See also City of Del City, 179 F.3d at 889 (holding that right to petition is not absolute, and in state employment context, employee must demonstrate that petition for which he was fired involved matter of public concern).
If MLBPA were being sued for libelous statements made in a litigation document filed with the court, McDonald would clearly allow the libel suit to continue as a matter of constitutional law. Compare Restatement (Second) of Torts § 587 (1977) (“A party to a private litigation ... is absolutely privileged' to publish defamatory matter concerning another in communications preliminary to a proposed judicial proceeding, or in the institution of or during the course and as a part of, a judicial proceeding in which he participates, if the matter has some relation to the proceeding.”). Likewise, statements made in a *892letter threatening litigation are not absolutely protected by the petition clause of the First Amendment and are subject to the principles of state common law and state statutory law.
However, even in the context of Cardtoons non-libel claims, it is clear that the right to petition simply does not grant MLBPA immunity from suit. The plain language of the First Amendment protects only those petitions which are made to “the Government.”6 As Judge Ebel noted in his dissent to the panel opinion:
The MLBPA’s cease-and-desist letter to Champs threatening suit was never sent to the government; did not ask the government for any response or “redress of grievances”; was not even known to the government prior to Cardtoons’ declaratory judgment action against the MLBPA; and did not ever result in any litigation.
Cardtoons TV, 182 F.Sd at 1141. A letter from one private party to another private party simply does not implicate the right to petition, regardless of what the letter threatens. Even the antitrust text cited by the panel majority notes that “a mere threat directed at one’s competitor to sue or to seek administrative relief does not involve or ‘petition’ the government....” Philip E. Areeda & Herbert Hovenkamp, Antitrust Law, § 205e at 237. See also Rodime PLC v. Seagate Technology, Inc., 174 F.3d 1294, 1307 (Fed.Cir.1999) (noting that meetings at which defendant persuaded potential licensees to end license negotiations with the plaintiff “had nothing to do with petitioning the government.”).
MLBPA asserts that the decisions of other circuits are to the contrary. See Glass Equip. Dev., Inc. v. Besten, Inc., 174 F.3d 1337 (Fed.Cir.1999); McGuire Oil Co. v. Mapco, Inc., 958 F.2d 1552 (11th Cir.1992); CVD, Inc. v. Raytheon Co., 769 F.2d 842 (1st Cir.1985); Coastal States Mktg., Inc. v. Hunt, 694 F.2d 1358 (5th Cir.1983). These cases are distinguishable. First, CVD merely held that “the threat of unfounded trade secrets litigation in bad faith is sufficient to constitute a cause of action under the antitrust laws, provided that the other essential elements of a violation are proven.” 769 F.2d at 851. We do not agree with MLBPA that the First Circuit thereby implied that good faith threats are immunized by Noerr-Pennington.
Second, and most importantly, all four cases arise in the antitrust context. As discussed earlier, both Coastal States and McGuire Oil grant immunity to prelitigation threats under a construction of the Sherman Act, not the right to petition. Neither Glass Equip. Dev. nor CVD even mention the right to petition. Although Glass Equip. Dev. does appear to treat both “actual or threatened infringement suits” the same for purposes of Noerr-Pennington immunity, 174 F.3d at 1344, we reject it, as well as the other three cases, to the extent they imply that the mere threat of suit between private parties constitutes a petition to the government.
The Supreme Court’s decision in Allied Tube & Conduit Corp. v. Indian Head, Inc., 486 U.S. 492, 108 S.Ct. 1931, 100 L.Ed.2d 497 (1988) also lends support to our conclusion.7 That case involved the National Fire Protection Association (NFPA), a private, voluntary organization which publishes the National Electrical Code. “Revised every three years, the Code is the most influential electrical code in the nation. A substantial number of state and local governments routinely *893adopt the Code into law with little or no change.” 486 U.S. at 495, 108 S.Ct. 1931. Changes in the Code could be approved by a simple majority vote of the members present at the NFPA’s annual meeting. Respondent proposed amending the Code to include polyvinyl chloride conduit as an approved type of electrical conduit. Petitioner, the Nation’s largest producer of steel conduit, feared that such approval would harm its business. It recruited over 150 people to attend the NFPA meeting and vote against the new proposal. Polyvinyl chloride conduit was rejected by a mere four votes, and respondent brought suit alleging violation of the Sherman Act.
Petitioner argued that it was immune from suit under Noerr-Pennington. The Court disagreed. “In this case, the restraint of trade on which liability was predicated was the Association’s exclusion of respondent’s product from the Code, and no damages were imposed for the incorporation of that Code by any government.” Allied Tube, 486 U.S. at 500, 108 S.Ct. 1931.
Here petitioner’s actions took place within the context of the standard-setting process of a private association. Having concluded that the Association is not a “quasi-legislative” body, we reject petitioner’s argument that any efforts to influence the Association must be treated as efforts to influence a “quasi-legislature” and given the same wide berth accorded legislative lobbying.
Id. at 504, 108 S.Ct. 1931. The Court specifically noted that communications with a private organization “did not take place in the open political arena, where partisanship is the hallmark of decision-making.” Id. at 506, 108 S.Ct. 1931. Without a petition to the government, “[t]he issue of immunity in this ease thus collapses into the issue of antitrust liability.” Id. at 509,108 S.Ct. 1931.
The present case is similar in many respects. MLBPA communicated with Champs in order to further its own business interests. Its efforts were successful when Champs refused to print the parody cards. Cardtoons brought suit alleging various violations of the law based upon MLBPA’s action. MLBPA raised Noerr-Pennington as a defense. We hold, to paraphrase Allied Tube, that because there was no petition of the government in the present case, the issue of immunity collapses into the issue of state law liability.8
While there are many persuasive policy arguments in favor of granting immunity to private threats of litigation, these do not override the clear language of the First Amendment. Such arguments are best addressed to the state legislative bodies which can craft state law accordingly. See e.g. Gary, supra note 3, at 73-77 (noting that state common law typically shields certain litigation activity from defamation and tortious interference suits).
In summary, we hold that when the basis for immunity is the right to petition, purely private threats of litigation are not protected because there is no petition addressed to the government.
REVERSED and REMANDED.
. This Court was faced with the issue but did not decide it in Quark, Inc. v. Harley, Nos. 96-1046, 96-1048, 96-1061, 1998 WL 161035, at *7 (10th Cir.1998) (unpublished order and judgment) ("Assuming, without deciding, that this circuit would extend the doctrine beyond the realm of antitrust litigation....”)
. Pennington extended this immunity to the right to petition the executive and California Motor Transport Co. v. Trucking Unlimited, 404 U.S. 508, 92 S.Ct. 609, 30 L.Ed.2d 642 (1972), further extended the doctrine to cover petitioning the courts, the third branch of government.
. See also Aaron R. Gary, First Amendment Petition Clause Immunity from Tort Suits: In Search of a Consistent Doctrinal Framework, 33 Idaho L.Rev. 67, 95 (1996) (“Innumerable federal and state courts have concluded that the Noerr-Pennington doctrine is rooted in the First Amendment right to petition and therefore must be applied to all claims implicating that right, not just to antitrust claims.”).
. Bill Johnson’s is a good example of the need to distinguish between antitrust cases based *890upon the two prongs of Noerr-Pennington and non-antitrust cases based solely on the right to petition. The dissent characterizes Bill Johnson’s as a direct application of Noerr-Pennington. However, such a characterization would lead to a direct conflict between Bill Johnson's and Professional Real Estate Investors, Inc. v. Columbia Pictures, Inc., (PRE), 508 U.S. 49, 113 S.Ct. 1920, 123 L.Ed.2d 611 (1993). Noerr-Pennington immunity, as defined in all of the Noerr antitrust line of cases, is immunity from liability. PRE, in the context of antitrust, held that a lawsuit is immune from liability unless it is a sham (i.e. objectively unreasonable or reasonable but brought in bad faith). See 508 U.S. at 60, 113 S.Ct. 1920. However, in Bill Johnson’s, the Supreme Court specifically declared, in the context of an NLRA dispute, that an employer who brought a non-sham suit could still be held liable, even though the right to petition protected the suit from being enjoined. 461 U.S. at 748-49, 103 S.Ct. 2161.
The conflict is apparent. Under the PRE standard, a plaintiff is immune from liability based upon a simple showing of objective reasonableness. Under Bill Johnson's, objective reasonableness is not enough and a court must further determine whether the plaintiff violated the law in bringing the suit. The only way to reconcile these cases is to limit them to the contexts in which they arose. PRE is an antitrust case; Bill Johnson's is not.
This distinction is important for two reasons. First, it cautions against describing Bill Johnson’s as an application of Noerr-Penning-ton immunity rather than Petition Clause immunity. Second, and more importantly, it demonstrates that PRE must be limited to the antitrust context. Outside of that context, the Petition Clause protects objectively reasonable lawsuits from being enjoined, but requires a court to look at the underlying statute to determine whether the initiator of the suit can be held liable. Therefore, given the non-antitrust context of this case, the dissent’s reliance on PRE in Part II, C is inapposite.
. The same is true of McGuire Oil Co. v. Mapco, Inc., 958 F.2d 1552 (11th Cir.1992), an antitrust case which relied upon Coastal States in granting immunity to threats of litigation. Although the Eleventh Circuit mentioned the right to petition as one basis for Noerr-Pennington immunity, it specifically protected the threats of litigation under an interpretation of the Sherman Act. See McGuire Oil, 958 F.2d at 1560 (holding that "threats, no less than the actual initiation of litigation, do not violate the Sherman Act”).
. The dissent does not address this plain language, but instead relies upon the concept of “breathing space,” the interest of private parties in vindicating their legal rights, and public policy arguments in arguing that such private threats should be constitutionally protected.
. We acknowledge that Allied Tube is an antitrust case applying Noerr-Pennington and are therefore careful to distinguish between propositions grounded solely on the Sherman Act and those also grounded in the right to petition.
. We also note in passing that an almost identical claim to that raised in this case was presented in Continental Ore Co. v. Union Carbide & Carbon Corp., 370 U.S. 690, 695, 82 S.Ct. 1404, 8 L.Ed.2d 777 (1962) (plaintiffs claimed that "[d]efendants in 1943, by open threats of reprisals, allegedly frustrated certain arrangements which Continental had with the Climax Molybdenum Corporation for the manufacture of ferrovanadium.”). Noerr immunity was discussed by the Court but was not mentioned in regard to this claim.