A top lawyer in President Bush's reelection campaign acknowledged Tuesday that he has been advising the veterans group seeking to discredit Democratic presidential nominee John F. Kerry's military record, an admission the Kerry campaign said is evidence the president's campaign is orchestrating a "smear" by the private group.

Benjamin L. Ginsberg, the chief outside counsel to the Bush campaign who also has advised Swift Boat Veterans for Truth, said in an interview: "I've done some work for them. . . . The law lets lawyers do that . . . and does not include lawyers among the coordinated political activities" that are prohibited by federal election law. He said two prominent Democratic lawyers are doing the same thing.

Other election lawyers agreed that the fact that Ginsberg, who also was active in Bush's 2000 campaign, has been giving legal advice to Swift Boat Veterans for Truth does not necessarily violate campaign finance law prohibiting collusion between campaigns and independent groups. But Ginsberg's dual roles complicate the Bush campaign's effort to rebut as "frivolous" Kerry's complaint that it is behind the Swift boat ads.

Asked about the Ginsberg matter Tuesday night, Bush campaign spokesman Steve Schmidt said: "There has been no coordination at any time between Bush-Cheney '04 and any 527 organization."

The veterans group's advertisements casting doubt on Kerry's Vietnam War decorations have turned the senator's earning of a Silver Star, a Bronze Star and three Purple Hearts during four months of duty in Vietnam into a dominant election issue this month. The Kerry campaign has filed a complaint with the Federal Election Commission charging illegal coordination between the Bush campaign and the group, known as a 527.

The 527s are nonprofit political groups named for a section of the tax code that covers them. They may raise and spend unlimited amounts of unregulated, or "soft," money from individuals, businesses and unions to run issue ads in federal elections. But the law prohibits 527 groups from coordinating their activities with individual political campaigns or political parties.

The type of work Ginsberg has done has not been deemed improper by Kerry's campaign. The law firm of Perkins Coie represents the Kerry campaign, and Robert Bauer, an election lawyer at the firm, represents the anti-Bush 527 group America Coming Together, which has been mobilizing voters for Kerry.

Ginsberg said that Joseph Sandler is a lawyer for both the Democratic National Committee and for the independent group MoveOn.org, which has run advertisements attacking Bush.

Bush on Monday said he is opposed to all advertising by 527 groups -- most of which has favored Kerry -- but would not specifically condemn the Swift boat veterans' advertisements.

In a letter Monday to the FEC, Tom Josefiak, general counsel to the Bush-Cheney campaign, said Kerry's complaint is "frivolous" and "baselessly alleging illegal coordination" between the two groups. Josefiak said the "complaint should be promptly dismissed." The campaign also contacted stations that might air a Kerry ad alleging a smear to warn of possible libel.

The Kerry campaign jumped on Ginsberg's admission Tuesday night. "If the Bush campaign truly disapproved of this smear, their top lawyer wouldn't be involved with the Swift boat veterans group,'' Kerry campaign spokesman Chad Clanton said.

Ginsberg said that a group of "decorated Vietnam War veterans came to me and said, 'We have an important point to get out in the debate under the First Amendment, the American right of free expression. . . . Help us,' they said, and I did."

In the interview, he said he did not participate in strategy planning or in the development of messages, and did not discuss Bush campaign activities with the Swift boat veterans, or vice versa. His relationship to the Swift boat group was first reported by the Associated Press.

On Saturday, the Bush campaign dismissed from its veterans steering committee a volunteer and Vietnam veteran, retired Col. Kenneth Cordier, who appeared in a Swift boat veterans ad. The campaign said Cordier had not previously disclosed his participation with the Swift boat group.

Democrats also said their allegation of collusion was supported by a flier at a Bush-Cheney office in Florida promoting a Swift boat event, and by close relationships in the past between backers of the veterans group and Bush aides such as political adviser Karl Rove.

Don Simon, an election-law expert with the campaign finance watchdog group Democracy 21, said Ginsberg's dual role "is not per se coordination" between the Bush campaign and the veterans group. That would occur only if Ginsberg has been transferring information between the two -- a question that likely would not be resolved before the election even if the FEC chooses to investigate the matter. But, Simon said that "as a matter of common sense, it certainly raises questions."

Larry Noble, who runs the Center for Responsive Politics watchdog group, said the Ginsberg situation is not by itself improper, but "when you're looking at common lawyers, it adds another level to it."

Edsall reported from Washington.