Campaign finance watchdog groups Thursday accused Democratic and Republican party committees of setting up organizations to evade a new ban on large corporate and union contributions. They asked the Federal Election Commission to investigate.

A complaint they were filing with the FEC accuses the National Republican Congressional Committee and the Democratic National Committee of trying to skirt the ban on the raising of soft money by national parties that took effect Nov. 6. The commission should look into it and "expeditiously stop the illegal activity,'' the complaint says.

The complaint accuses the NRCC of setting up a group called The Leadership Forum and says the Democratic National Committee and its chairman, Terry McAuliffe, are trying to get around the soft money ban through the recently established Democratic State Parties Organization.

Fred Wertheimer, co-founder of Democracy 21, one of four groups filing the complaint, said other new organizations that popped up in the days before the new campaign finance law took effect will also be reviewed. Besides banning the national parties from collecting soft money, the law prohibits the use of such contributions in federal elections.

"This is Round One of the campaign,'' Wertheimer said. Joining Democracy 21 in the complaint were Common Cause, the Center for Responsive Politics and The Campaign and Media Legal Center.

Officials at both parties called the complaint groundless and said they had nothing to do with the groups.

"It's a complete publicity stunt,'' DNC spokeswoman Maria Cardona said of the complaint.

Don McGahn, general counsel for the NRCC, said the campaign finance watchdog groups were wrong on the facts and on the law.

"They state without a whole lot of analysis that this, what do they call it, The Leadership Forum, is affiliated with us,'' McGahn said. "That's simply not the case, and I think they make a lot of factual assumptions that aren't accurate.''

McGahn confirmed that the NRCC transferred $1 million to the forum shortly before the law took effect Nov. 6, but said that was allowed under FEC rules.

He said the complaint seemed to be an effort to scare donors and others, and added that donors shouldn't be scared off.

The Leadership Forum has asked the FEC for advice on the issue of affiliation "to make sure they're on the up and up,'' McGahn said.