BOSTON - Lawrence Mayor Michael Sullivan is forming a campaign exploratory committee - his most serious step yet as he considers a run to succeed Congressman Martin Meehan.

Sullivan, a Republican, said the committee includes his brother, Kevin Sullivan, a former mayor of Lawrence and one-time state transportation and finance secretary in Republican administrations. The two-term mayor said he would decide by the end of this month if he will run for the House of Representatives.

"There are a lot of personal things to consider," said Sullivan, who has two teenaged daughters. "The whole lifestyle change, traveling from Washington back to Lawrence."

Then there's what he'd be leaving behind at City Hall.

"What would this disruption mean to my commitment to Lawrence?" Sullivan asked. "I want to finish the term. I want to do that because there are major initiatives."

Those initiatives include overseeing the opening of the new high school in September, moving the downtown Essex Street development forward and completing a new police station.

Also, if Sullivan were to win, there would have to be a special election to replace him as mayor. That would cost the city money, just as the election to replace Meehan could cost Lawrence $200,000. Meehan, a Lowell Democrat, is resigning from Congress on July 1 to become chancellor of the University of Massachusetts Lowell.

But the allure of representing the 5th Congressional District may overshadow those concerns.

"In my lifetime, there are not many opportunities that come around when you can call yourself a U.S. representative, and that's a real honor to serve in the House," Sullivan said.

As Sullivan moves closer to making a decision, the rest of the GOP field is taking shape.

Former Buffalo Bills and New England Patriots defensive lineman Fred Smerlas told The Eagle-Tribune he will decide before the weekend. Smerlas, who has an 8-year-old son, said family is a major consideration.

"I'm a strong family man," said Smerlas, a radio and television football analyst. "I'm going to look at what impact it will have on my life and my child's life."

Still, Smerlas said he's interested. "Complaining all the time doesn't do anything," he said.

Republican Charles McCarthy of Dunstable, who ran against Meehan in 2002, is also weighing a run. McCarthy could not be reached for this story.

Former Congressman Peter Torkildsen, whose name has come up as a possible candidate, told The Eagle-Tribune he is not interested in running.

Also yesterday, state Rep. James Miceli, D-Wilmington, was the only legislator running for Meehan's seat to back a Republican plan to have Meehan help pay for the special election to replace him.

Republicans circulated the resolution that would instruct Congress to allow federal campaign funds to offset the cost of special congressional elections. It also would allow part of Meehan's leftover congressional salary to be tapped.

Meehan has called the measure absurd. But Miceli said he supported it because it allows Meehan to voluntarily disburse some of his $5.1 million war chest to help financially strapped cities and towns pay for an unanticipated election.

The other Democratic lawmakers seeking Meehan's seat didn't sign on.

"I think it's not for the right reasons," said Rep. Barry R. Finegold, D-Andover. "We should be busy doing other things than worrying about that."

"I think it is a partisan stunt," said Rep. James Eldridge, D-Acton. "It's just the kind of thing that makes citizens disenchanted. ... I think it's garbage."