WASHINGTON – The chairman of the Federal Election Commission said yesterday he wants to rein in nonprofit groups that spend millions of unregulated dollars to influence federal elections by scrutinizing what they tell their donors – not just what they later say in public advertisements.

The commission meets today under intense scrutiny to vote on proposed rules to limit so-called 527 groups, which have become the vehicles for wealthy individuals, corporations, and labor unions to inject multimillion-dollar donations into federal politics.

Together with two other commissioners, Bradley Smith has proposed a rule that would limit the soft-money contributions flowing to 527 groups based on what the groups say they want to do with the money.

Groups that raise more than $1,000 by saying they seek to elect or defeat a federal candidate would be limited to accepting small donations for their activities – rather than the multimillion dollar donations some groups have pulled in.

“It would not only be what you spend the money for, but what you say when you solicit it from people” that would trigger regulation, Mr. Smith told The New York Sun yesterday.

He said the proposal would “capture a lot of the groups” that have been the targets of complaints, and is “more far-reaching than critics give it credit for.”

The critics prefer a competing proposal they say is much more demanding and dismiss as “obstructionist” the proposal of Mr. Smith, vice chairwoman Ellen Weintraub, and commissioner David Mason.

“The games being played by Commissioners Smith, Weintraub, and Mason represent an irresponsible dereliction of duty by public officials who are charged with enforcing the nation’s campaign finance laws,” said the president of Democracy 21, Fred Wertheimer, and the president of the Campaign Legal Center, Trevor Potter, in a joint statement.

Mr. Smith dismissed the critics. “They are getting increasingly shrill and people are laughing at them,” he said. “The problem we have here is there are some radical elements of the reform movement who want to regulate more than the law regulates, and they are mad because we refuse to do it.”

Critics have said today’s hearing is critical for the credibility of the FEC.

The commissioners came under intense criticism from advocates of tougher campaign finance rules and from some congressional Republicans when they voted last May to postpone the decision until after the November elections, a move which allowed the well-financed anti-Bush groups such as Moveon.org and America Coming Together to continue activities critics say are clearly political.

Recently, the anti-Kerry group Swiftboat Veterans for Truth has also become the target of a complaint pending before the FEC for accepting large donations and using the money on a public campaign disparaging the Democratic presidential nominee.

“There if no conceivable justification for the FEC to fail to act on Thursday to make clear that 527 groups who are out to influence federal elections must comply with federal campaign finance rules,” said Senator McCain, a Republican of Arizona, who has written legislation that would overhaul the agency. He called today’s meeting “one last chance” for the commission to “act responsibly.”

“The most significant feature of meeting is going to be the fact that the FEC is unable to act. We’re going to see another 3-3 tie that’s going to confirm that the FEC is structured for deadlock and has to be abolished and replaced with a different body,” said a campaign finance specialist at Public Citizen, Craig Holman, who speculated the vote was the result of pressure from Republicans.

“Had the Republican Party not raised such a ruckus, it is very likely the FEC would have avoided the issue … The hearings have gone so far as to cast a very negative eye on the FEC for its inability to act,” he said.

The commission is scheduled to study a new proposal put forward by its staff lawyers that would require the 527 groups to register with the FEC as political action committees if their activities show that their “major purpose” is to influence federal elections – that is, if more than half of its spending in any given year is on public messages that refer to a candidate for federal office.

Unlike an earlier proposal that the FEC rejected, the new rule would allow more flexible treatment for charities, such as pro- and anti-abortion groups or environmental groups, which only involve themselves in election campaigns as a secondary activity to other activities.

While advocates of the campaign finance laws praised the proposal, some specialists cautioned that it should not be adopted in haste.

“I don’t see there is any great hurry. The regulations can’t take effect until after the November elections and that gives us time to do it right,” said a Washington attorney who represents nonprofit advocacy organizations, John Pomeranz. He said the proposal was “close to something we can live with” but outlined several potential technical flaws.

Specialists say clarity is desperately needed.

“In the absence of the general counsel proposal, it has been uncertain how you know whether you cross that line so winning elections is now your major purpose. That provides a major benefit of certainty,” said an election law specialist at the Ohio State University’s Moritz College of Law, Edward Foley.

Last month, Senator Lott of Mississippi held the committee’s first oversight hearing into the commission in more than six years, and accused the commission of “punting” the issue of 527s and “begging off” other tough issues. He also proposed reducing the number of commissioners to five in order to break the deadlock.

Mr. Smith said an even number of commissioners ensures that rules pass only with bipartisan support. He dismissed the deadlocked votes as a cause for concern.

“If one of them were to lose a vote in the Senate, I don’t think they would call for abolishing the Senate,” he said.