BOSTON — Since declaring his split from House Speaker Salvatore DiMasi last week, state Rep. David Torrisi says he's received a lot of behind-the-scenes support from his Merrimack Valley colleagues.

But, he's not sure whether any of them will follow suit.

Torrisi, D-North Andover, said he will not vote for DiMasi when the Democratic caucus meets Wednesday to choose its leadership, citing the allegations of ethical wrongdoing that are dogging the speaker.

In retaliation, Torrisi expects DiMasi will remove him from his chairmanship on the Committee on Labor and Workforce Development in the upcoming weeks.

"My colleagues that I have talked to have been very positive, very encouraging," Torrisi said. "They tell me to do what I believe. ... A lot of them aren't prepared to do what I'm doing."

Torrisi shared his decision with DiMasi, who named him as a chairman and attended his wedding in 2006, during a one-on-one meeting on Dec. 22.

Valley legislators are calling Torrisi's move a brave one that they would expect from him.

"Agree with him or not, David is very principled," said state Sen. Steven Baddour, D-Methuen. "Nobody ever questions his moral compass."

A close DiMasi associate, Richard Vitale, was indicted earlier this month on charges he lobbied illegally, with prosecutors claiming Vitale was in repeated and direct touch with DiMasi over ticket resale legislation that cleared the House.

Separately, DiMasi has refused to discuss reports that a federal grand jury has launched an investigation into the awarding of a state software contract to a firm that paid DiMasi associates, including, indirectly, Vitale.

"I don't think this is going away," Torrisi said last week of the controversies. "I think this is a huge distraction for the membership."

Torrisi's decision is the most formal signal of the membership's uneasiness about following DiMasi. Torrisi was first elected to the House in 1998.

Local representatives interviewed say they aren't sure how they'll vote on Wednesday.

"I respect David for doing what he thinks is the right thing to do," Andover state Rep. Barbara L'Italien said, adding that she was still mulling over her vote. "Honestly, I don't know yet."

L'Italien, who did not vote for former Speaker Thomas Finneran in 2003, said she knows how difficult going against the grain can be.

"I'm still not in leadership," she said. "I still sit in a basement office ... It's obviously harder working from the outside, but it can be done."

The vote against Finneran was one of her first votes in the House.

"I remember taking the phone call from Finneran and he asked me whether I'd vote for him. I had to explain why I wasn't. It was a little scary," she said.

Rep. Harriet Stanley, D-Newbury, said she knows Torrisi and respects his thought process, adding that she left him a phone message in the wake of his announcement.

"If there's only one person running, obviously that kind of makes your decision for you," she said. "I think that many of my colleagues are sitting and waiting."

Torrisi is aware there are consequences to his act, Stanley said, referring to a tax vote she took that went against the House speaker that stripped her of a committee chairmanship.

"If I had to do it over again, I would do it exactly the way I did it," Stanley said.

On the other hand, State Rep. Michael Costello, D-Newburyport, has pledged his support for DiMasi, asking what kind of friend he would be if he deserted an embattled friend.

"I think it's a decision every representative has their own conclusion on," Torrisi said.

Democratic state Reps. Barry Finegold of Andover, Brian Dempsey of Haverhill, Linda Dean Campbell of Methuen and William Lantigua of Lawrence , did not return calls for comment.

Torrisi said his constituents have offered nothing but encouragement.

"I received calls over the last two months, and the calls I was getting were asking me not to vote for the speaker on Jan. 7," Torrisi said. " It was part of my calculus, but not the only factor."

Two other House members — Ways and Means Chairman Robert DeLeo and Majority Leader John Rogers — have signaled over the past few months that they are interested in becoming Speaker role, but neither is expected to run against DiMasi.

Torrisi plans to vote "present" when the House convenes Wednesday.

DiMasi has said he will seek another term in office, while some members have privately said they are uncomfortable lining up behind him while he battles the controversies over his role in government action that benefited his friends and associates. The speaker has denied wrongdoing.

Torrisi has said he was uncertain whether DiMasi had done anything wrong.

If DiMasi revokes Torrisi's chairmanship, he could lose some of his office staff. His office employs two personal aides, two committee staffers and receptionist.

"I think that's pretty obvious," Torrisi said last week, laughing when asked whether he expected removal. "I'd imagine I'd lose a staff member or two. ... I'm prepared to deal with the consequences of this and I think my staff is too."

Material from the Statehouse News Service was used in this report.