delivered the opinion of the Court.
We are called upon to determine the effect of Rule 12 (b)(2) of the Federal Rules of Criminal Procedure on a post-conviction motion for relief which raises for the first time a claim of unconstitutional discrimination in the composition of a grand jury. An indictment was returned in the District Court charging petitioner Davis, a Negro, and two white men with entry into a federally insured bank with intent to commit larceny in violation of 18 U. S. C. §§2 and 2113 (a). Represented by appointed counsel,1 petitioner entered a not-guilty plea at his arraignment and was given 30 days within which to file pretrial motions. He timely moved to quash his indictment on the ground that it was the result of an illegal arrest, but made no other pretrial motions relating to the indictment.
On the opening day of the trial, following voir dire of the jury, the District Judge ruled on petitioner’s pretrial motions in chambers and ordered that the motion to quash on the illegal arrest ground be carried with the case. He then asked twice if there were anything else before commencing trial. Petitioner was convicted and *235sentenced to 14 years’ imprisonment. His conviction was affirmed on appeal. 409 F. 2d 1095 (CA5 1969).
Post-conviction motions were thereafter filed and denied, but none dealt with the issue presented in this case. Almost three years after his conviction, petitioner filed the instant motion to dismiss the indictment, pursuant to 28 U. S. C. § 2255, alleging that the District Court had acquiesced in the systematic exclusion of qualified Negro jurymen by reason of the use of a “key man” system of selection,2 an asserted violation of the “mandatory requirement of the statute laws set forth ... in title 28, U. S. C. A. Section 1861, 1863, 1864, and the 5th amendment of the United States Constitution.” 3 His challenge only went to the composition of the grand jury and did not include the petit jury which found him guilty. The District Court, though it took no evidence on the motion, invited additional briefs on the issue of waiver. It then denied the motion. In its memorandum opinion it relied on Shotwell Mfg. Co. v. United States, 371 U. S. 341 (1963), and concluded that petitioner had waived his right to object to the composition of the grand jury because such a contention is waived under Rule 12 (b)(2) unless raised by motion prior to trial. Also, since the “key man” method of selecting grand jurors had been openly followed for many years prior to petitioner’s indictment; since the same grand jury that indicted petitioner indicted his two white accomplices; and since the *236case against petitioner was “a strong one,” the court determined that there was nothing in the facts of the case or in the nature of the claim justifying the exercise of the power to grant relief under Rule 12 (b) (2) for “cause shown.”
The Court of Appeals affirmed on the basis of Shotwell, supra, and Rule 12 (b)(2). Because its decision is contrary to decisions of the Ninth Circuit in Fernandez v. Meier, 408 F. 2d 974 (1969), and Chee v. United States, 449 F. 2d 747 (1971), we granted certiorari to resolve the conflict.
Petitioner contends that because his § 2255 motion alleged deprivation of a fundamental constitutional right, one which has been recognized since Strauder v. West Virginia, 100 U. S. 303 (1880), his case is controlled by this Court’s dispositions of Kaufman v. United States, 394 U. S. 217 (1969), and Sanders v. United States, 373 U. S. 1 (1963), rather than Shotwell Mfg. Co. v. United States, supra, and Rule 12 (b)(2). Accordingly, he urges that his collateral attack on his conviction may be precluded only after a hearing in which it is established that he “deliberately bypassed” or “understandingly and knowingly” waived his claim of unconstitutional grand jury composition. See Fay v. Noia, 372 U. S. 391 (1963), and Johnson v. Zerbst, 304 U. S. 458 (1938).
I
Rule 12 (b)(2) provides in pertinent part that “[defenses and objections based on defects in the institution of the prosecution or in the indictment . . . may be raised only by motion before trial,” and that failure to present such defenses or objections “constitutes a waiver thereof, but the court for cause shown may grant relief from the waiver.” By its terms, it applies to both procedural and constitutional defects in the institution of prosecutions which do not affect the jurisdiction of the *237trial court. According to the Notes of the Advisory Committee on Rules, the waiver provision was designed to continue existing law, which as exemplified by this Court’s decision in United States v. Gale, 109 U. S. 65 (1883), was, inter alia, that defendants who pleaded to an indictment and went to trial without making any non-jurisdictional objection to the grand jury, even one unconstitutionally composed, waived any right of subsequent complaint on account thereof. Not surprisingly, therefore, the Advisory Committee’s Notes expressly indicate that claims such as petitioner’s are meant to be within the Rule’s purview:
“These two paragraphs [12 (b)(1) and (2)] classify into two groups all objections and defenses to be interposed by motion prescribed by Rule 12 (a). In one group are defenses and objections which must be raised by motion, failure to do so constituting a waiver. . . .
“. . . Among the defenses and objections in this group are the following: Illegal selection or organization of the grand jury . . . .” Notes of Advisory Committee following Fed. Rule Crim. Proc. 12, 18 U. S. C. App.
This Court had occasion to consider the Rule’s application in Shotwell Mfg. Co. v. United States, supra, a case involving tax-evasion convictions. In a motion filed more than four years after their trial, but before the conclusion of direct review, petitioners alleged that both the grand and petit jury arrays were illegally constituted because, inter alia, “the Clerk of the District Court failed to employ a selection method designed to secure a cross-section of the population.”4 371 U. S., at 361-362. *238Deeming the case controlled by Rule 12 (b)(2), the District Court held a hearing to determine whether there was “cause” warranting relief from the waiver provision and it found that “the facts concerning the selection of the grand and petit juries were notorious and available to petitioners in the exercise of due diligence before the trial.” Id., at 363. It concluded that their failure to exercise due diligence combined with the absence of prejudice from the alleged illegalities precluded the raising of the issue, and the Court of Appeals affirmed. In this Court, petitioners conceded that Rule 12 (b) (2) applied to their objection to the grand jury array, but they denied that it applied to the petit jury. Both objections were held foreclosed by the petitioners’ years of inaction, and the lower courts’ application of the Rule was affirmed.
Shotwell thus confirms that Rule 12 (b) (2) precludes untimely challenges to grand jury arrays, even when such challenges are on constitutional grounds.5 Despite the strong analogy between the effect of the Rule as construed in Shotwell and petitioner’s § 2255 allegations, he nonetheless contends that Kaufman v. United States, supra, establishes that he is not precluded from raising *239his constitutional challenge in a § 2255 proceeding.6 See Fay v. Noia, supra. We disagree.
In Kaufman, the defendant in a bank robbery conviction sought collateral relief under § 2255 alleging that illegally seized evidence had been admitted against him at trial, over a timely objection, and that this evidence resulted in the rejection of his only defense to the charge. The application was denied in both the District Court and the Court of Appeals on the ground that it had not been raised on appeal from the judgment of conviction and “that a motion under § 2255 cannot be used in lieu of an appeal.” 394 U. S., at 223. This Court reversed, however, holding that when constitutional claims are asserted, post-conviction relief cannot be denied solely on the ground that relief should have been sought by appeal. Ibid.
But the Court in Kaufman was not dealing with the sort of express waiver provision contained in Rule 12 (b) (2) which specifically provides for the waiver of a par*240ticular kind of constitutional claim if it be not timely asserted. The claim in Kaufman was that the applicable provisions of § 2255 by implication forbade the assertion of a constitutional claim of unlawful search and seizure where the defendant failed to assert the claim on appeal from the judgment of conviction.7 See, e. g., Sunal v. Large, 332 U. S. 174, 179 (1947). The Court held that the statute did not preclude the granting of relief on such a claim simply because it had not been asserted on appeal, where there was no indication of a knowing and deliberate bypass of the appeal procedure. But here the Government’s claim is not that § 2255 itself limits or precludes the assertion of petitioner’s claim, but that the separate provisions of Rule 12 (b) (2) do so. Kaufman, therefore, is dispositive only if the absence of a statutory provision for waiver in § 2255 and the federal habeas statute by implication precludes the application to post-conviction proceedings of the express waiver provision found in the Federal Rules of Criminal Procedure.
Shotwell held that a claim of unconstitutional grand jury composition raised four years after conviction, but while the appeal proceedings were still alive, was governed by Rule 12 (b) (2). Both the reasons for the Rule and the normal rules of statutory construction clearly indicate that no more lenient standard of waiver should *241apply to a claim raised three years after conviction simply because the claim is asserted by way of collateral attack rather than in the criminal, proceeding itself.
The waiver provisions of Rule 12 (b) (2) are operative only with respect to claims of defects in the institution of criminal proceedings. If its time limits are followed, inquiry into an alleged defect may be concluded and, if necessary, cured before the court, the witnesses, and the parties have gone to the burden and expense of a trial. If defendants were allowed to flout its time limitations, on the other hand, there would be little incentive to comply with its terms when a successful attack might simply result in a new indictment prior to trial. Strong tactical considerations would militate in favor of delaying the raising of the claim in hopes of an acquittal, with the thought that if those hopes did not materialize, the claim could be used to upset an otherwise valid conviction at a time when reprosecution might well be difficult.
Rule 12 (b) (2) promulgated by this Court and, pursuant to 18 U. S. C. § 3771, “adopted” by Congress, governs by its terms the manner in which the claims of defects in the institution of criminal proceedings may be waived. See Singer v. United States,, 380 U. S. 24, 37 (1965). Were we confronted with an express conflict between the Rule and a prior statute, the force of § 3771, providing that “[a] 11 laws in conflict with such rules shall be of no further force or effect,” is such that the prior inconsistent statute would be deemed to have been repealed. Cf. Sibbach v. Wilson & Co., 312 U. S. 1, 10 (1941). The Federal Rules of Criminal Procedure do not ex proprio vigore govern post-conviction proceedings, and had Congress in enacting the statutes governing federal collateral relief specifically there dealt with the issue of waiver, we would be faced with a difficult question of repeal by implication of such a provision by the later *242enacted rules of criminal procedure. But Congress did not deal with the question of waiver in the federal collateral relief statutes, and in Kaufman this Court held that, since § 2255 had not spoken on the subject of waiver with respect to claims of unlawful search and seizure, a particular doctrine of waiver would be applied by this Court in interpreting the statute.
We think it inconceivable that Congress, having in the criminal proceeding foreclosed the raising of a claim such as this after the commencement of trial in the absence of a showing of “cause” for relief from waiver, nonetheless intended to perversely negate the Rule’s purpose by permitting an entirely different but much more liberal requirement of waiver in federal habeas proceedings. We believe that the necessary effect of the congressional adoption of Rule 12 (b) (2) is to' provide that a claim once waived pursuant to that Rule may not later be resurrected, either in the criminal proceedings or in federal habeas, in the absence of the showing of “cause” which that Rule requires. We therefore hold that the waiver standard expressed in Rule 12 (b) (2) governs an untimely claim of grand jury discrimination, not only during the criminal proceeding, but also later on collateral review.
Our conclusion in this regard is further buttressed by the Court’s observation in Parker v. North Carolina, 397 U. S. 790, 798 (1970), decided the year after Kaufman, that “[w]hether the question of racial exclusion in the selection of the grand jury is open in a federal habeas corpus action we need not decide.” The context of the Court’s language makes it apparent that the question was framed in terms of waiver and timely assertion of such a claim in state criminal proceedings. But if the question were left open with respect to state proceedings, it must have been at least patently open with respect to *243federal habeas review of federal convictions, where Congress is the lawgiver both as to the procedural rules governing the criminal trial and the principles governing collateral review.
II
The principles of Rule 12 (b) (2), as construed in Shot-well, are not difficult to apply to the facts of this case. Petitioner alleged the deprivation of a substantial constitutional right, recognized by this Court as applicable to state criminal proceedings from Bush v. Kentucky, 107 U. S. 110 (1883), through Alexander v. Louisiana, 405 U. S. 625 (1972). But he failed to assert the claim until long after his trial, verdict, sentence, and appeal had run their course. In findings challenged only halfheartedly here, the District Court determined that no motion, oral or otherwise, raised the issue of discrimination in the selection of the grand jurors prior to trial. The Court of Appeals affirmed, and on petition for rehearing conducted its own search of the record in a vain effort to see whether the files or docket entries in the case supported petitioner’s contention that he had made such a motion. We will not disturb the coordinate findings of these two courts on a question such as this.
The waiver provision of the Eule therefore coming into play, the District Court held that there had been no “cause shown” which would justify relief. It said:
“Petitioner offers no plausible explanation of his failure to timely make his objection to the composition of the grand jury. The method of selecting grand jurors then in use was the same system employed by this court for years. No reason has been suggested why petitioner or his attorney could not have ascertained all of the facts necessary to present the objection to the court prior to trial. The same *244grand jury that indicted petitioner also indicted his two white accomplices. The case had no racial overtones. The government’s case against petitioner was, although largely circumstantial, a strong one. There was certainly sufficient evidence against petitioner to justify a grand jury in determining that he should stand trial for the offense with which he was charged. . . . Petitioner has shown no cause why the court should grant him relief from his waiver of the objection to the composition of the grand jury.....”
In denying the relief, the court took into consideration the question of prejudice to petitioner. This approach was approved in Shotwell where the Court stated:
“[W]here, as here, objection to the jury selection has not been timely raised under Rule 12 (b)(2), it is entirely proper to take absence of prejudice into account in determining whether a sufficient showing has been made to warrant relief from the effect of that Rule.” 371 U. S., at 363.
Petitioner seeks to avoid this aspect of Shotwell by asserting that there both lower courts had found that petitioners were not prejudiced in any way by the alleged illegalities whereas under Peters v. Kiff, 407 U. S. 493 (1972), prejudice is presumed in cases where there is an allegation of racial discrimination in grand jury composition. But Peters dealt with whether or not a white man had a substantive constitutional right to set aside his conviction upon proof that Negroes had been systematically excluded from the state grand and petit juries which indicted and tried him. Three Justices dissented from the Court’s upholding of such a substantive right on the ground that no prejudice had been shown, and three concurred separately in the *245judgment. But the three opinions delivered in Peters, supra, all indicate a focus on the existence of the constitutional right, rather than its possible loss through delay in asserting it. The presumption of prejudice which supports the existence of the right is not inconsistent with a holding that actual prejudice must be shown in order to obtain relief from a statutorily provided waiver for failure to assert it in a timely manner.
We hold that the District Court did not abuse its discretion in denying petitioner relief from the application of the waiver provision of Rule 12(b)(2), and that having concluded he was not entitled to such relief, it properly dismissed his motion under § 2255. Accordingly, the judgment of the Court of Appeals is
Affirmed.
Petitioner was represented throughout the trial by competent, court-appointed counsel, whose advocacy prompted the Court of Appeals to compliment him saying:
“We have rarely witnessed a more thorough or more unstinted expenditure of effort by able counsel on behalf of a client.” 409 F. 2d 1095, 1101 (CA5 1969).
The use of the “key man” system was approved in. Scales v. United States, 367 U. S. 203, 259 (1961), affirming 260 F. 2d 21, 44-46 (CA4 1958). The adoption of the Jury Selection and Service Act of 1968, 28 U. S. C. §§ 1861-1869, has precluded its further use.
Petitioner also alleged that a timely oral motion in open court prior to trial was made preserving for him the right to contest the grand jury array, and that a law student who was researching the grand jury array was stopped from seeing him.
Petitioner attempts to distinguish Shotwell on the ground that the case “involved legal irregularities which did not rise to the *238dimension of the fundamental constitutional right asserted” herein. (Brief for Petitioner 18.) At 362-363 of the Court's opinion in Shotwell, however, the majority accepted petitioners’ assertion of constitutional deprivation at face value before rejecting their claims on the basis of Rule 12 (b) (2).
We are comforted in this conclusion by the concurrence of all but one of the courts of appeals that have considered the issue. See Moore v. United States, 432 F. 2d 730, 740 (CA3 1970) (en banc); Juelich v. Harris, 425 F. 2d 814 (CA7 1970); United States v. Williams, 421 F. 2d 529, 532 (CA8 1970); Bastillo v. United States, 421 F. 2d 131 (CA5 1970); and Poliafico v. United States, 237 F. 2d 97 (CA6 1956). Contra, Fernandez v. Meier, 408 F. 2d 974 (CA9 1969).
Petitioner relies on the reasoning of Fernandez, supra, in arguing that a different waiver rule should apply in § 2255 proceedings. In that case, the defendant argued that the exclusion of Spanish Americans from his grand and petit juries constituted a deprivation of constitutional right. The claim was untimely raised and the Court of Appeals conceded that failure to present it as provided in Rule 12 (b) (2) resulted in a waiver. Relying, however, on this Court’s decisions in Fay v. Noia, 372 U. S. 391 (1963), and Sanders v. United States, 373 U. S. 1 (1963), that court held that collateral relief could be denied under § 2255 only upon a showing of a “knowing and deliberate by-pass” of a timely objection. Petitioner concedes that the court misread Sanders, supra, but he argues that it applied the correct waiver rule. Although we find it difficult to conceptualize the application of one waiver rule for purposes of federal appeal and another for purposes of federal habeas corpus, we will nonetheless give consideration to petitioner’s claim that the cases interpreting the federal habeas corpus statute set the applicable standard.
The Court in Kaufman made reference to the possibility of the denial of § 2255 relief as a result of a deliberate bypass of the suppression procedures established in Fed. Rule Crim. Proc. 41 (e). Kaufman v. United States, 394 U. S. 217, 227 n. 8 (1969). But it had no occasion to consider that Rule’s effects on § 2255 motions since there “[a]ppointed counsel had objected at trial to the admission of certain evidence on grounds of unlawful search and seizure,” id., at 220 n. 3, and the District Court’s rationale for denying relief was that “this matter was not assigned as error on Kaufman’s appeal from conviction and is not available as a ground for collateral attack . . . .” See id., at 219.