The Democrat-dominated Massachusetts House has given preliminary approval to a bill that would strip Republican Gov. Mitt Romney (search) of the power to appoint a successor to John Kerry's Senate seat if he is elected president.

The bill, which the Senate approved last week, would require a special election within 160 days after a vacancy is created. The winner would serve the remainder of Kerry's unexpired term, which ends in 2008.

The issue has national implications in the narrowly divided U.S. Senate, with Republicans eager to pick up one of Massachusetts' two Senate seats and Democrats eager to hold on to Kerry's office.

The House version of the bill, approved Tuesday by a vote of 116-34, will now go back to the Senate and then to the House again for final approval before heading to Romney's desk.

Romney, who adamantly opposes the bill, is likely to either veto the bill or send it back with amendments. The Senate passed its version of the bill by a 32-8 margin — more than the two-thirds needed to override a veto.

Romney has said a "shotgun" election would favor candidates with political organizations and deep pockets. He says he's not opposed to a special election, but should be allowed to appoint a replacement during the interim to ensure the state has full representation in the Senate.

"Why is this such a pressing issue? Ahh, because it's politics. It's all politics. Heaven forbid the governor gets to make an appointment," said Republican state Rep. George Peterson.

Democrats said it was Republicans who were motivated more by politics than policy.

"A governor is going to make some kind of calculus for political purposes. That is true of either party," said Democratic state Rep. William Straus. "We think the people can get it right."

Romney called on the campaigning Kerry last week to resign from the Senate immediately, saying he has missed key votes, one of which cost Massachusetts up to $75 million in federal unemployment insurance dollars.

A Kerry campaign spokesman said it was Republicans who blocked the extension of unemployment benefits, not Kerry.

A poll Wednesday in the Boston Herald said Romney is the best hope for Republicans to win Kerry's seat, showing Romney in close races with the only two unofficial candidates — Democratic Reps. Edward J. Markey (search) and Martin T. Meehan (search). The Boston Globe said Markey and Meehan each have raised more than $1 million for a potential Senate race.

The poll found Romney would beat Meehan 44 percent to 41 percent, with 15 percent of those surveyed unsure. Markey would beat Romney 43-40, with 17 percent unsure.

The poll of 500 registered voters was conducted June 15-28 by RKM Research and Communications, and has a plus or minus 4.4 percentage point margin of error.