The three Democrats at the agency responsible for enforcing campaign finance rules attended last week's Democratic convention at taxpayers' expense, and Republican members of the Federal Election Commission plan to do the same later this month.

"We're up here in theory as ambassadors for the FEC," Commissioner Scott Thomas said of his trip to the presidential nominating convention in Boston with fellow Democratic Commissioners Ellen Weintraub and Danny McDonald.

The Democratic and Republican parties invited all six commissioners to both conventions, Weintraub said. Though they didn't attend, some GOP commissioners sent staff members to the Democratic gathering, and Thomas might attend the Republican convention, she said.

Two of the FEC's Republicans, Michael Toner and Chairman Brad Smith, plan to go to the GOP convention in New York.

"It's one of the few chances where you get to talk with local party officials and really get a sense for how the laws are affecting them," Smith said.

Smith said he wanted to visit last week's convention but had to skip it because of surgery. Toner also initially planned to join the three Democratic commissioners in Boston, but other obligations precluded him from going, an aide said.

In all, a dozen people from the FEC attended the Boston convention at an estimated cost of $18,000, commission spokesman Bob Biersack said. The commission expects travel costs for the GOP convention to be about the same.

Bill Allison, a spokesman for the Center for Public Integrity, a government watchdog group, said it's better for commissioners to cover their convention costs using taxpayer money than it would be if they went at the expense of the political parties or others they regulate, but he questioned why they were going to the party gatherings at all.

"I think it shows how cozy a system we have with the FEC," Allison said. "The big problem with the FEC is it's not independent. It does have this connection to the parties. You're asking people from the parties to run a commission whose job is to be tough on the parties and their candidates, and that's inherently problematic."

Weintraub, a former Democratic campaign lawyer, said it was her first presidential convention, and she thought it was valuable to see how the party spent the roughly $15 million in government money it received to help finance the event.

"It puts me in a better position when we audit the committee later on," said Weintraub, the FEC's vice chairwoman. "I've watched conventions on television before and I don't know that you get the same sense of it."

Weintraub said she didn't receive any questions on campaign finance there.

"I wasn't there to provide legal advice to people. I was there as an observer," she said.

Commissioners have been attending the conventions for years, Biersack said.

Larry Noble, head of the watchdog group Center for Responsive Politics, said the convention trips could be a good thing, depending on what commissioners do with the experience.

"If by observing all the corporate funding of conventions they saw the error of their ways in allowing that corporate funding, their attendance would be a positive," said Noble, former FEC general counsel. "However, I don't hold out hope for that."