Rep. Brian Dempsey, chairman of the powerful House Ways and Means Committee who was widely viewed as a likely successor to Speaker Robert DeLeo, announced Thursday he will be leaving the Massachusetts Legislature to join a prominent lobbying firm.
The Haverhill Democrat has served in the House for more than 25 years and was named by DeLeo in 2011 to head the committee that writes the House version of the state's $40 billion annual budget and reviews scores of bills before they are sent to the floor for debate.
ML Strategies said Dempsey will join the firm's Boston office in September as senior vice president and chief operating officer.
In-depth news coverage of the Greater Boston Area.
Dempsey said in a statement that he was moving on to a new chapter in his life and called it an "incredible honor" to serve his constituents in elective office. He was a Haverhill city councilor before winning election to the House.
DeLeo, a Winthrop Democrat, called Dempsey a close friend and colleague, noting the two entered the House together in 1991.
"In terms of the job he did as chair of Ways and Means, he's been one of the best I have ever seen at it," DeLeo told reporters. "He will be deeply missed by all of us here, but it appears to be a great opportunity for him and his family."
Before the surprise announcement certain to rock the state political establishment, Dempsey had been considered the most likely heir apparent to DeLeo, based on their close relationship and Dempsey's considerable knowledge of legislation and the inner workings of the House.
DeLeo has been speaker since 2009 and hasn't given any indication he's prepared to relinquish the post anytime soon. In 2015, he engineered a change in legislative rules to eliminate an eight-year term limit for speakers, enabling him to be re-elected in January to another two-year term as House leader, his fifth.
On Thursday, DeLeo said he planned to run for his seat in 2018 but had not thought ahead to how much longer he wished to remain as speaker.
Other key members of DeLeo's leadership team include Majority Leader Ron Mariano, of Quincy; Patricia Haddad, of Somerset, who holds the title of Speaker Pro Tempore; and assistant majority leaders Byron Rushing, of Boston, Paul Donato, of Medford, and Michael Moran, of Boston. Dempsey's departure could also leave the door open for a dark horse candidate to emerge as the speaker's eventual successor.
Recently, Dempsey was the lead House negotiator in talks that produced a compromise with the Senate on an overdue $40.2 billion budget for the fiscal year that started July 1. A shortfall in state tax collections forced lawmakers to slash revenue estimates in the budget by $733 million, and spending by at least $400 million. Republican Gov. Charlie Baker is reviewing the spending plan.
State lobbying law includes a one-year "cooling off period," meaning Dempsey will be prohibited during the first 12 months of his new job from directly lobbying state legislators on any issue.
Stephen Tocco, chief executive of ML Strategies, called Dempsey a "dynamic leader with a track record for success." The firm, with offices in Boston and Washington and an array of high-powered clients, also employs former Republican Gov. William Weld.