Appellants seek attorney’s fees for challenging a Washington statute which was amended, mooting their action, before the case was heard. We affirm the district court’s denial of their motion for fees.

*186 I. FACTS

Four Washington minor political parties 1 (the minor parties) challenged the constitutionality of a Washington statute 2 which effectively prohibited members of minor political parties from voting in state primary elections. Their 1976 suit was preceded by meetings in 1971 with the Secretary of State and the introduction of corrective bills in the Washington legislature. In 1977 the statute was amended to eliminate the objectionable provision. House and Senate Journals for the months during which the legislation was considered make no mention of the minor parties’ suit. 3

A legislator said in an affidavit made one year after the statute was amended:

Affidavit of State Representative Nelson.

After the Secretary sought dismissal of the suit for lack of a case or controversy, the minor parties moved for an award of fees pursuant to the Civil Rights Attorney’s Fees Award Act (Act), 42 U.S.C. § 1988 . 4 Without hearing oral argument, the district court found the subject action moot, granted the Secretary’s motion to dismiss, and denied the motion for fees.

A motion for reconsideration was denied 5 and the order denying fees is appealed. Although the minor parties were willing to waive oral argument, we heard counsel at the Secretary’s request.

il. DISCUSSION

The question on review is whether the district court erred in finding that the minor parties were not “prevailing parties” within the meaning of § 1988.

1. Standard of Review

At oral argument, appellants urged us to treat Judge Tanner’s denial of the motion for fees as a summary judgment. They contend that he erred in not holding an evidentiary hearing.

We disagree. A full evidentiary hearing was unnecessary. Appellants requested neither a hearing nor oral argument on their motion. The affidavits and record before the court allowed it to consider all factors requisite to an award of fees. The district court did not abuse its discretion in relying on the affidavits and record to determine the case. See Williams v. Alioto, 625 F.2d 845, 849 (9th Cir. 1980), cert. denied, - U.S. -, 101 S.Ct. 1723 , 68 L.Ed.2d 213 (1981).

*187 2. Legislative Interpretation

The history of the Act 6 makes clear Congress’ intent that a plaintiff need not obtain formal relief in order to recover fees. S.Rep.No. 94-1011, 94th Cong., 2d Sess. 5, reprinted in [1976] U.S.Code Cong. & Admin.News, 5908, 5912. See also, Williams v. City of Fairburn, 640 F.2d 635 (5th Cir. 1981); Dawson v. Pastrick, 600 F.2d 70 (7th Cir. 1979); Kopet v. Esquire Realty Co., 523 F.2d 1005 (2d Cir. 1975); Parham v. Southwestern Bell Tel. Co., 433 F.2d 421 (8th Cir. 1970).

A party who “vindicates his rights through a consent judgment,” 7 or “has prevailed on an important matter in the course of litigation, even when he ultimately does not prevail on all issues,” 8 may be eligible. Moreover, when a plaintiff’s lawsuit “acted as a catalyst which prompted the appellee to take action ... ”, 9 the Senate Report directs that he be awarded fees. The Par-ham “catalyst” language was expanded by the Fourth Circuit in Bonnes v. Long, 599 F.2d 1316 (4th Cir. 1979). It focused on:

Id. at 1319 , [1976] U.S.Code Cong. & Ad.News at 5910-11. 10

The Senate Report’s broad and strident language prescribes a generous attitude towards the award of fees:

S.Rep., supra at 3, [1976] U.S.Code Cong. & Admin.News at 5910.

This circuit has interpreted Congress’ mandate to require that the Act “must be liberally construed to achieve Congress’ purpose ‘to encourage compliance with and enforcement of the civil rights laws’”. C ollins v. Chandler Unified School Dist., 644 F.2d 759, 764 (9th Cir. 1981) (citations omitted); Dennis v. Chang, 611 F.2d 1302, 1306 (9th Cir. 1980). 11

Other courts have identified as prevailing parties those who “essentially succeed in obtaining the relief [sought],” 12 or who were “successful in their efforts” to obtain a statutory amendment. 13

The efforts of prevailing parties have been labelled variously as “at least a ‘contributing ... factor’ in the bringing about of [the desired] procedural changes,” 14 although not the “sole cause”, as a “material factor in bringing about the defendant’s action” 15 , and as contributing “in a significant way.” 16

*188 In Iranian Students Assoc. v. Sawyer, 639 F.2d 1160 (5th Cir. 1981), the district court awarded fees for appellee’s challenge of a ban on campus demonstrations and marches even though “remedial action by the defendant effectively moot[ed] the controversy subsequent to the filing of the lawsuit." Id. at 1163 . On appeal, however, the cause was remanded for an evidentiary hearing to determine “whether the appellee’s suit was a significant catalyst to the recission of the ban .... ” Id. at 1164 . The court of appeals explained that the causal relation between the lawsuit and the relief received “must be more than simple knowledge that litigation may occur,” and that the chronology of events, while a “factor to consider” was “clearly not definitive.” Id. at 1163 . 17

It is clear, then, that the courts have required consistently that plaintiffs seeking to qualify as “prevailing parties” establish some sort of clear, causal relationship between the litigation brought and the practical outcome realized.

C. Appellant’s Showing

In this case the minor parties argue that, although they did not prevail formally, their suit was successful because it “contributed in a significant way to the legislative action ... [which] vindicated the rights that the suit sought to protect .... ”

In support, they rely on the affidavit of a single legislator. As a member of the Conference Committee which drafted the legislation, Representative Nelson’s statement might be entitled to some weight if it had been made contemporaneously with the passage of the legislation. Coming one year later, it is entitled to no weight and cannot be relied on as indicative of legislative motivation or intent. See Gunther v. County of Washington, 623 F.2d 1303, 1317-18 (9th Cir. 1979). But assuming, arguendo, that his affidavit represents a statement on behalf of other legislators, it still does not persuade us that appellant’s suit was at least a “material factor” in the legislative process.

The affidavit states only that the suit was “discussed”, not that it played a causal role in passage of the amendment. No other evidence of the minor parties’ catalytic role has been produced and the appellants have never suggested that any exists. Indeed, there is uncontroverted evidence that proposed changes in the statute had been tossed around for years, often initiated by the Secretary’s own office. The minor parties have failed to show that theirs was a sufficiently influential role in this process.

The district court correctly denied the motion for attorney’s fees. 18

AFFIRMED.

. The American Constitutional Party, the Libertarian Party, the Bicentennial Reality Party, and the Socialist Workers’ Party.

. Wash.Rev.Code § 29.24.

. The minor parties point out, however, that the House and Senate Journals of the Washington legislature ordinarily contain only a sparse procedural history of a bill, rather than the substantive history often found in committee reports, testimony, floor debates, and speeches.

. Proceedings in the case were suspended from January 1977 to June 1978, during which no non-emergency motions were heard, pending the appointment of Judge Tanner to fill the vacant district court judgeship in Tacoma. Thus, while the motion to dismiss was filed January 16, 1977, the statute was amended during the 1977 legislative session, and Judge Tanner was appointed in May 1978. He found the action moot and denied the motion for fees on July 18, 1978.

. But in response to the minor parties’ motion for clarification, Judge Tanner cited 42 U.S.C. § 1988 , which provides that a court: in its discretion, may allow the prevailing party ... a reasonable attorneys fee as part of the costs.

He further explained that the memoranda and affidavits submitted by both parties did not warrant a finding that the minor parties’ litigation “served as a ‘catalyst for change’, forcing the Washington Legislature to amend unconstitutional laws, and thereby achieving a ‘valuable public service.’ ” Thus, the minor parties did not qualify for attorneys fees as the “prevailing party.” District Court’s Order of September 26, 1979.

. S.Rep.No.94-1011, 94th Cong., 2d Sess., reprinted in [1976] U.S.Code Cong. & Admin.News 5908.

. S.Rep.No.94-1011, supra note 6 at 5, [1976] U.S.Code Cong. & Ad.News at 5913.

. S.Rep.No.94-1011, supra note 6 at 5, [1976] U.S.Code Cong. & Ad.News at 5912.

. Parham v. Southwestern Bell Tel. Co., 433 F.2d 421, 429-30 (8th Cir. 1970) (cited with approval in S.Rep.No.94-1011, supra note 6 at 5, [1976] U.S.Code Cong. & Ad.News at 5912.).

; See also, Dawson v. Pastrick, 600 F.2d 70, 79 (7th Cir. 1979).

. See also, Seattle School Dist. v. Washington, 633 F.2d 1338, 1349 (9th Cir. 1980).

. Bagby v. Beal, 606 F.2d 411, 415 (3d Cir. 1979); see also Morrison v. City of Ayoob, 627 F.2d 669 (3d Cir. 1980), cert. denied, - U.S. -, 101 S.Ct. 898 , 66 L.Ed.2d 828 (1981).

. Armstrong v. Reed, 462 F.Supp. 496, 498 (N.D.Miss.1978). But see, Huntley v. Community School Board, 579 F.2d 738 , 742 (2d Cir. 1979) (plaintiff won nominal damages of $100, at most a “moral victory” of insufficient magnitude to warrant award of attorney’s fees).

. Ross v. Horn, 598 F.2d 1312, 1321-22 (3d Cir. 1979), cert. denied, 448 U.S. 906 , 100 S.Ct. 3048 , 66 L.Ed.2d 1136 (1980). See also, Panitch v. Wisconsin, 451 F.Supp. 132 (E.D.Wis.1978) (plaintiffs action contributed to enactment of state law).

. Morrison v. Ayoob, 627 F.2d 669, 671 (3d Cir. 1980), cert. denied, - U.S. -, 101 S.Ct. 898 , 66 L.Ed.2d 828 (1981).

. Bonnes v. Long, 599 F.2d 1316, 1319 (4th Cir. 1979).

. See also, Ross v. Horn, 598 F.2d 1312, 1322 (3d Cir. 1979), cert. denied, 448 U.S. 906 , 100 S.Ct. 3048 , 66 L.Ed.2d 1136 (1980) (“chronology of events strongly suggests ... a causal relationship”). In Sawyer , the circuit court remanded for an evidentiary hearing on whether the plaintiffs lawsuit was a significant catalyst for change because the record was inadequate. But in that case, the appellants had formally requested such a hearing of the district court.

. Because we hold appellants were not prevailing parties within the meaning of the Act, we do not decide whether the requested fees were unreasonable.