The Republican National Committee (search) on Friday asked about 250 television stations to pull a liberal group's ads critical of President Bush.

The RNC sent the stations a letter Friday suggesting the outlets may be complicit in breaking campaign finance laws if they air the MoveOn.org Voter Fund (search) ads. It asked them to decline to broadcast the ads.

The RNC argues that the group, financed by so-called "soft money," is spending it on ads to influence a federal election. The campaign finance law broadly bars the use of such corporate, union and unlimited donations to influence federal elections.

MoveOn began airing ads Thursday critical of Bush's policies. MoveOn founder Wes Boyd (search) said the ads are legal, and added that the group isn't concerned by the RNC's letter. The ads were financed with unlimited donations from individuals -- one form of soft money.

The ads were originally to air in 17 presidential battleground states over five days at a cost of $1.9 million. Boyd said the group decided Friday to spend $1 million more to run an ad criticizing Bush's economic policies for an additional week in several states.

In the letter, RNC chief counsel Jill Holtzman Vogel wrote, "As a broadcaster licensed by the Federal Communications Commission, you have a responsibility to the viewing public and to your licensing agency to refrain from complicity in any illegal activity, specifically in this case, violations of our nation's federal election laws."

Federal Election Commission (searchspokesman Bob Biersack said the FEC could only determine whether there was anything amiss in the MoveOn ad buy by reviewing the details, something it typically would do if a complaint was filed against the group.