WASHINGTON (AP) — A Republican group that backs abortion rights will start an ad campaign this weekend in Iowa and New Hampshire portraying Mitt Romney as a flip-flopper and drawing attention to a questionnaire he filled out in 2002 endorsing legal abortions.

The ads by the Republican Majority for Choice suggest Romney's current anti-abortion stance is politically motivated. The group will spend more than $100,000 to air a 30-second television spot in Iowa and New Hampshire and run full-page ads Sunday in the Des Moines Register, the Concord Monitor and the New Hampshire Union Leader.

"He's an opportunist," Jennifer Blei Stockman, national co-chair of Republican Majority for Choice, said in an interview. "It's important for voters to know who they are voting for."

Stockman and other members of the group's board have donated to the presidential campaign of former New York Mayor Rudy Giuliani, an advocate of abortion rights. Stockman contributed $2,300 to Giuliani's campaign last May.

But Stockman said the group itself has not endorsed a candidate in the presidential contest. She stressed that the Republican Majority for Choice and the Giuliani campaign have had no discussions regarding the ad campaign.

Earlier this month in Iowa, Giuliani expressed disapproval of any outside advertising effort that might surface on his behalf akin to the one John McCain's supporters have launched in South Carolina. McCain has asked his donors not to bankroll such campaigns.

Asked whether he would make the same request of his backers, Giuliani said: "My donors aren't, so that's not really a fair question. No one has suggested that there's any such thing going on on my behalf. I would not want to see such a thing going on on my behalf. I would never ask anybody to do that, and I would ask people not to do that because all it does is confuse your race."

Romney, the former governor of Massachusetts, has won the backing of some key religious conservatives but is still dogged by suspicions about his stance on some social issues. He has said he changed his view on abortion in 2004 during debates over stem cell research. He said he became convinced he could not publicly support abortion rights while being personally opposed to abortion.

Romney spokesman Kevin Madden said Wednesday, "The political group that is attacking and distorting Governor Romney's position is desperately trying to destroy the Republican Party's position on the issue of protecting life, while also supporting Mayor Giuliani and his pro-choice position that is at odds with grass-roots conservative Republicans."