AUGUSTA, Maine (AP) — Maine’s U.S. Senate candidates, Tom Allen and Susan Collins, are sparring over a new series of campaign ads aired by a third party.

Collins, a Republican who is seeking her third term, called on Allen on Sunday to denounce the TV ads being aired by VoteVets.Org. The ads take Collins to task for votes on the Iraq war, but Collins says they attempt to distort her record.

“This is the latest in a series of ads, which are paid for by out-of-state, special interest political groups, to attack Senator Collins since 2007. These same groups have already spent more than $1 million on attack ads against Senator Collins,” the campaign said in a statement.

Allen, Maine’s 1st District Democratic congressman, said in a statement through his campaign spokeswoman that he has been the target of weeks of false and negative attacks by Collins’ allies, and agrees that distortions “have no place in the race.”

“Congressman Allen stands by his call to third parties to keep TV and radio ads positive,” says the statement by campaign spokeswoman Carol Andrews.

But it said the differences between Collins and Allen on the Iraq war are clear, with Allen calling for a deadline for withdrawal from Iraq and Collins supporting “an open-ended commitment.”

Allen has been targeted in a series of ads that harshly criticize his support for the Employee Free Choice Act, also known as the “card-check” bill, which would allow workers to unionize when they get a majority of workers to sign cards favoring a union.

In one ad, an actor who portrayed a mob leader in HBO’s “The Sopranos” pressures a worker to sign a union recognition card. Both Allen’s and Collins’ campaigns condemned the ads, which are also financed by outside political groups.

TV spots defending the card check bill have since appeared.