WASHINGTON — The John Kerry presidential campaign has filed a complaint with the Federal Election Commission alleging the veterans' group behind an anti-Kerry TV ad was illegally coordinating its efforts with the Bush-Cheney campaign.

The Kerry campaign cited "recent press reports" and the group's own statements.

The Bush campaign denied the allegation, as did the organization that aired the ad.

Political campaigns often file complaints with the FEC, but the commission rarely intervenes quickly enough to alter the course of a race.

Under the McCain-Feingold Bipartisan Campaign Reform Act passed in 2002, nonparty groups are prohibited from spending soft money — corporate, union or unlimited donations — in federal elections. But new outside fundraising groups, most of them pro-Democratic, contend the ban does not apply to them, so they are pouring soft money into issue ads and get-out-the-vote efforts focused on this year's presidential race.

Campaign watchdogs have asked the Federal Election Commission to block such spending by these groups, often called “527s,” after a federal tax provision that lets groups raise unlimited funds to spend in support of a candidate as long as they don’t give money directly to the candidate or coordinate with the candidate’s campaign on the content and timing of political messages.

The group airing the ads against Kerry that have provoked the current furor, Swift Boat Veterans for Truth, is one of these "527" groups.

Attacks on Kerry's Vietnam war record may be beginning to have an impact, polls suggest, amid raised voices and new TV ads on a subject at least temporarily dominating debate in the close presidential race.

Democrats are laboring to deflect the questioning of Kerry's record with fresh ads touting his fitness for national command, even as the White House mocks the Massachusetts senator as "losing his cool" over claims he lied to win military medals in Vietnam.

Kerry wasn't going to let such claims pass, spokeswoman Stephanie Cutter shot back on Aug. 20, saying "John Kerry is a fighter and he doesn't tolerate lies from others."

The anti-Kerry swift-boat group, meanwhile, has distributed a second ad to the news media and said it would begin airing it next week in Pennsylvania, Nevada and New Mexico. The ad mixes clips of a youthful Kerry talking about war atrocities in testimony to Congress in 1971 with images of veterans condemning his remarks.

The intense late-August back-and-forth underscored the closeness of the race for the White House and came as polls offered the first hint that the questioning of Kerry's medal-winning service in the Vietnam War — allegations that he strongly condemned this week as lies — were taking a political toll.

One poll found that more than half the voters questioned had seen or heard of an ad by Swift Boat Veterans for Truth that accused Kerry of lying about events that earned him five medals a generation ago. The University of Pennsylvania's National Annenberg Election Survey also found that 44% of self-described independent voters found the ad at least somewhat believable.

Separately, a CBS News poll found a sharp drop in Kerry's support among veterans since the end of the Democratic National Convention that highlighted his war record.

Polls after the convention indicated Kerry had made considerable progress toward the campaign's goal of establishing him as a battle-tested veteran ready to assume command in an era of terrorism. Several veterans who served with him have campaigned alongside him, strongly supporting his combat record and calling him a hero.

In a new commercial that officials said was filmed last week, the Democratic Party showed retired Air Force Gen. Merrill A. McPeak saying he had endorsed President Bush four years ago but was backing Kerry now.

That message is sharply at odds with the image portrayed in the anti-Kerry ad that the nominee denounced on Aug. 19 when he said Bush was relying on front groups to "do his dirty work."

"I do think that Senator Kerry losing his cool should not be an excuse for him to lash out at the president with false and baseless attacks," White House spokesman Scott McClellan told reporters in Crawford, Texas, on Aug. 20.

"We've already said we weren't involved in any way in these ads," he said. "We've made that clear."

Kerry's campaign then trumpeted a political flier from Florida advertising a "pro-USA political rally" that appeared to show the veterans' group and the local Bush-Cheney campaign as sponsors.

Records show that Bob Perry, a Houston homebuilder who is helping to finance the anti-Kerry commercials, was well-enough known to Bush to earn an invitation to visit the then-Texas governor.