OPINION
NIGRO, Justice.This case presents the novel issue of whether a claim that a statute was enacted in violation of the procedures set forth in the Pennsylvania Constitution may be barred by laches. For the reasons discussed below, we conclude that laches may apply and we affirm the Commonwealth Court’s decision that Appellants’ challenge to the Low-Level Radioactive Waste Disposal Act, eight years after its enactment, is barred.
Appellants Gene Stilp, Eric Epstein and Thomas Linzey, appearing pro se, filed a complaint in mandamus in Commonwealth Court requesting injunctive and declaratory relief against Appellees Treasurer Barbara Hafer, Governor Thomas Ridge and the Commonwealth of Pennsylvania. Appellants are Pennsylvania residents who are officers and directors of Stop the Illegal Low-Level Program In Pennsylvania. They allege that the Low-Level Radioactive Waste Disposal Act, 35 P.S. §§ 7130.101-7130.905 (1993), was enacted in violation of procedures set forth in Article III of the Pennsylvania Constitution.
The Low-Level Radioactive Waste Disposal Act, also known as Act 12, was enacted in 1988 in part to implement Pennsylvania’s duties under the Appalachian States Low-Level Radioactive Waste Compact. 35 P.S. § 7130.102. Pennsylvania, Maryland, Delaware, and West Virginia entered into the Compact to provide for regional management and disposal of low-level radioactive waste as required by federal legislation. See id. §§ 7125.1-7125.4 (setting forth Compact). Pennsylvania is obligated under the Compact to develop a regional facility on a timely basis. Id. § 7125.1. Under Act 12, the Pennsylvania Department of Environmental Protection has the duty to develop and implement a comprehensive program for the *131disposal of low-level radioactive waste. Id. § 7130.301. The Environmental Quality Board has the duty to adopt regulations to implement Act 12. Id. § 7130.302.
In their Complaint, filed on March 29, 1996, Appellants asked the court to declare Act 12 void and to enjoin the Appellees from enforcing it, or from making any expenditures under the Act, based upon alleged procedural irregularities in its enactment.1 In addition, Appellants asked the court to enjoin Appellees from enforcing or making expenditures under the Low-Level Radioactive Waste Disposal Regional Facility Act, 35 P.S. §§ 7131.101-7131.1101, which in part establishes a low-level radioactive waste disposal regional facility siting fund.
In response to Appellants’ Complaint, Appellees filed an Answer and New Matter alleging that Appellants’ action is barred by laches. On December 6, 1996, Appellants moved for a peremptory judgment.2 Appellants maintained that Appellees admitted in their Answer that the Act was passed in violation of constitutional procedures. On April 24, 1997, Appellees moved for summary judgment based upon the defense of laches.3 After an unsuccessful attempt to intervene, the Appalachian States Low-Level Radioactive Waste Commission, the agent of the parties to the Compact, filed an amicus curiae brief supporting Appellees’ motion for summary *132judgment and opposing Appellants’ motion for peremptory-judgment.
The Commonwealth Court granted Appellees’ motion for summary judgment and held that Appellants’ action is barred by laches. It found that laches applies to procedural challenges to statutes under the Constitution, that Appellees established that Appellants did not act diligently in filing their Complaint, and that the delay prejudiced the Commonwealth. The Commonwealth Court also denied Appellants’ motion for a peremptory judgment. Appellants appealed the decision as of right to this Court under 42 Pa.C.S. § 723.
Laches is an equitable doctrine that bars relief when a complaining party is guilty of want of due diligence in failing to promptly institute an action to the prejudice of another. Sprague v. Casey, 520 Pa. 38, 45, 550 A.2d 184, 187 (1988). Appellants argue that the Commonwealth Court erred in granting summary judgment based upon laches because the doctrine may not be used to defeat a constitutional challenge to a statute. While Appellees concede that laches may not bar a constitutional challenge to the substance of a statute, they maintain that laches may bar a challenge like the one in this case, which only attacks the process by which the statute at issue was enacted eight years ago.
Whether laches may bar a constitutional challenge to a statute based upon procedural deficiencies in its enactment is an issue of first impression in Pennsylvania. Appellees correctly maintain that Pennsylvania authority to date does not preclude the application of laches to such a challenge. The Supreme Court addressed a laches argument in Sprague v. Casey, 520 Pa. 38, 550 A.2d 184 (1988), where a taxpayer challenged an upcoming judicial election and argued that the Constitution prohibits the election of judges in a general election year. The Commonwealth defendants and judicial nominees argued that laches barred the challenge, which was brought over six months after the taxpayer had notice of the election. In rejecting the laches defense, the Court found that the defendants did not establish that the taxpayer failed to use *133due diligence in filing the action or that they were prejudiced by the delay. Id. at 47, 550 A.2d at 188.
Although the Court’s consideration of the laches defense on the merits supports its application to procedural challenges, Appellants rely on dicta in Sprague stating that “laches and prejudice can never be permitted to amend the Constitution.” Id. at 47, 550 A.2d at 188. However, in making this general statement, the Court looked to its prior decisions in Wilson v. School Distr. of Philadelphia, 328 Pa. 225, 195 A. 90 (1937), and Commonwealth v. Gilligan, 195 Pa. 504, 46 A. 124 (1900), which involved constitutional challenges to the substantive provisions of statutes. These cases do not resolve whether laches may bar a constitutional challenge based upon procedural deficiencies in a statute’s enactment.4 In addition, to the extent Sprague could be construed otherwise, it is factually distinguishable since the taxpayer sought to prevent an unconstitutional act from occurring rather than challenge an act that already occurred.
Other states have held that laches applies to a constitutional procedural challenge to a statute’s enactment where there is no substantive objection to the statute. In Schaeffer v. Anne Arundel County, 338 Md. 75, 656 A.2d 751 (1995), a taxpayer filed a complaint in 1993 alleging that a county did not provide notice of an ordinance enacted in 1989 as required by the Maryland Constitution. The Maryland Court of Appeals5 held that the claim was barred by laches. The court distinguished substantive challenges to statutes and explained that parties could not take a “wait and see” approach and challenge ordinances many years after their enactment on procedural grounds. See also Schulz v. State of New York, 81 N.Y.2d 336, 615 N.E.2d 953, 599 N.Y.S.2d 469 (1993) (laches barred *134constitutional challenge to public financing statute based upon lack of voter approval); Citizens for Responsible Gov’t v. Kitsap County, 52 Wash.App. 236, 758 P.2d 1009 (1988) (laches barred due process challenge to ordinance based upon inadequate notice). But see Sears v. Treasurer and Receiver General, 327 Mass. 310, 98 N.E.2d 621 (1951) (laches is not a defense to a constitutional challenge to a law’s execution).6
Having reviewed this authority, we agree with the Commonwealth Court that laches may apply where a challenge to a law is made on procedural grounds years after its passage. Our legislative processes are available to the public when a new law is enacted. Otherwise, as aptly stated by our lower court, courts would revisit statutes that are constitutionally sound in substance and that have been relied upon by the citizens of this Commonwealth.
Even if laches applies, Appellants further maintain that the Appellees have not established the doctrine’s two elements. Appellees must establish (1) a delay arising from Appellants’ failure to exercise due diligence and (2) prejudice to the Appellees resulting from the delay. See Sprague, 520 Pa. at 45, 550 A.2d at 187-88. Whether laches is established requires a factual determination based upon the circumstances of each case. Id. As such, it is generally an inappropriate basis for summary judgment unless the relevant facts are not in dispute. Tudor Development Group, Inc. v. United States Fidelity & Guaranty Co., 768 F.Supp. 493, 496 (M.D.Pa.1991).
With respect to whether Appellants acted diligently, Appellees maintain that Act 12 was enacted in February of 1988 and that Appellants had all the information necessary at that time to challenge the Act on procedural grounds. Appellants, however, argue that there is no evidence that they knew the facts related to their claim in 1988.
*135The Commonwealth Court properly stated that the test for due diligence is not what a party knows, but what he might have known by the use of information within his reach. See Sprague, 520 Pa. at 45, 550 A.2d at 188. The procedures used to enact Act 12 in 1988 were published in the Legislative Journal and available to the public. The provisions of the Constitution that the Appellees purportedly violated were also readily available. Appellants themselves state in their brief that the proof necessary to sustain their Complaint lies in the legislative record. Thus, the facts related to this issue are undisputed and the Commonwealth Court properly concluded from them that Appellants did not act diligently in pursuing their claim.
Appellees have also established prejudice as a result of the eight year delay. Prejudice may be found where there has been some change in the condition or relations of the parties which occurs during the period the complainant failed to act. Tudor Development Group, 768 F.Supp. at 495-96. In support of their summary judgment motion, Appellees submitted evidence that the Department of Environmental Protection entered into a contract for the siting, development and operation of the regional disposal facility. In addition, regulations have been promulgated to implement Act 12. See 25 Pa.Code §§ 236.1-236.710. Appellees also submitted the Auditor General’s Audit Reports of the fund established for expenses related to the facility’s development, and the Department’s annual reports to the General Assembly detailing activity on the project.
Appellants argue that Appellees are not prejudiced by the delay because construction has not yet begun on the disposal facility and any information that has been gathered can be used again when the statute is reenacted. These arguments, however, do not refute that Appellees have changed their position and expended time and money in reliance on the validity of Act 12. Having entered into contractual relations and worked for eight years implementing Act 12, Appellants’ delay prejudices the Appellees.
*136In sum, we hold that the doctrine of laches may bar a challenge to a statute based upon procedural deficiencies in its enactment. We find the relevant facts here undisputed and conclude that Appellants did not act diligently in pursuing their claim and the Appellees are prejudiced by the delay.7 We thus affirm the decision of the Commonwealth Court.
NEWMAN, J., files a dissenting opinion in which FLAHERTY, C.J., joins.. Specifically, Appellants allege Act 12 was so altered on its passage through the General Assembly that its original purpose changed in violation of Article III, Section 1 of the Pennsylvania Constitution. Appellants further allege that Article III, Section 2 was violated because Act 12 was not referred to a committee after its original purpose was changed. Appellants also allege that Article III, Section 4 was violated because the bill was not considered on three days in either House after its original purpose was changed.
. A peremptory judgment may be entered if the plaintiff's right to judgment is clear. Pa. R. Civ. P. 1098.
. Summary judgment may be granted where the pleadings, depositions, answers to interrogatories, and admissions on file, together with affidavits, if any, show that there is no genuine issue of material fact and that the moving party is entitled to judgment as a matter of law. Pa. R. Civ. P. 1035. Rules 1035.1-1035.4, which replaced Rule 1035, took effect several months after the filing of Appellants’ action.
. Wilson v. School Distr. of Philadelphia, 328 Pa. 225, 195 A. 90 (1937), involved a challenge to a statute granting taxing power to a non-elected school board in violation of the Pennsylvania Constitution. Commonwealth v. Gilligan, 195 Pa. 504, 46 A. 124 (1900), involved a challenge to a statute that allegedly violated the constitutional prohibition on local laws regulating school district affairs.
. The Maryland Court of Appeals is the highest appellate court in Maryland.
. Appellants' reliance upon authority rejecting laches as a defense to a substantive constitutional challenge is misplaced. Asbury Park Press, Inc. v. Woolley, 33 N.J. 1, 161 A.2d 705 (1960), involved a constitutional challenge to an apportionment law based upon census figures. State ex rel. Baker v. Gray, 133 Fla. 23, 182 So. 620 (1938), addressed a constitutional challenge to a statute allegedly violating the prohibition of local laws regulating fees of counly officers.
. We need not address the merits of Appellants’ motion for peremptory judgment given our conclusion that laches bars their claims.