State lawmakers are privately speculating that Richard Brodsky, a longtime Democratic assemblyman of Westchester who has fallen short in his efforts to win statewide office, has his eye on the speaker’s seat.

The lawmaker’s recent outbursts of criticism of Governor Spitzer, and his statements suggesting that legislative leaders have made a strategic error by failing to uphold the reputation of the Legislature, have led some of his colleagues to believe that Mr. Brodsky is seeking to position himself as a successor to Speaker Sheldon Silver.

The speculation has increased as word has spread that Mr. Brodsky has been organizing dinners with several members of his conference in the past month.

Word has apparently reached Mr. Silver.

A source close to Mr. Silver said Mr. Brodsky’s recent activities have piqued the curiosity of the speaker, a politician sensitive to the climate of his conference. “He was asking what Brodsky was up to,” the source said.

No one is suggesting Mr. Brodsky is cooking up a plot against Mr. Silver, 63, who survived a coup attempt led by Michael Bragman in 2000 and has given no indication that he plans to step down.

There’s talk, however, that Mr. Brodsky, 60, is seeking to make the case that he is the one member of the Assembly who can stand toe-to-toe with the governor and protect the power of the Legislature.

Lawmakers say Mr. Brodsky, after an abortive run for attorney general last year and a failed quest to become comptroller, is setting aside his statewide office ambitions to become a more powerful player in the Assembly.

“Should the speaker decide to step down at some point, I definitely think that Richard would pursue it,” a former assemblyman of Rockland County, Ryan Karben, said. “To the extent that he’s trying to send a message to his colleagues that he would jealously guard legislative prerogatives, that would clearly help that kind of campaign.”

In the past two months, Mr. Brodsky has clashed with the governor on several major fronts. During the battle over the appointment of the comptroller, he led the charge that Mr. Spitzer was encroaching on the constitutional power of the Legislature by trying to influence whom lawmakers elected to replace the disgraced comptroller, Alan Hevesi.

Claiming to speak on behalf of his colleagues, Mr. Brodsky in February wrote a letter to the governor saying he was appalled by the Spitzer administration’s assertion that the job should not go to a member of the Legislature. “We will no longer allow those attacks to go unanswered,” Mr. Brodsky wrote.

Mr. Brodsky has also assumed the role of public relations tsar for a Legislature that has taken a beating in the press.

Last month, he wrote an op-ed published in the New York Times arguing that the Legislature serves as an important check on the abuse of executive power. The article carried the implicit criticism that legislative leaders have not adequately defended the institution from the flood of criticism.

“We failed to make our case about what we do well. When attacks were made, we were silent. When falsehoods were spread, they went unanswered. We enabled the creation of a poisonous, corrosive atmosphere that still cripples our ability to meet our constitutional obligations,” he wrote.

Immediately after the budget passed, Mr. Brodsky accused Mr. Spitzer of shortchanging Westchester County schools, saying in a letter to Mr. Spitzer’s budget director that was co-signed with other lawmakers from Westchester that the county had been “singled out for harm.” Mr. Brodsky’s criticism stood in contrast to Mr. Silver’s steady support of the governor during negotiations.

As chairman of the Committee on Corporations, Authorities and Commissions, Mr. Brodsky built a reputation during the Pataki administration as a tenacious watchdog over quasi-public agencies, shedding light on patronage and insider dealing through his subpoena power and public hearings.

While his critics don’t question his intelligence or his passion for public service, Mr. Brodsky’s abrasive and bumptious style has worn out the patience of some of his colleagues, who question whether his temperament is suited for a job that requires the ability to assuage egos, command loyalty, and unite a disparate group of more 100 lawmakers.

Mr. Brodsky said he loves his work in the Assembly and dismisses talk about his political plans as idle speculation. He does not, however, rule out an interest in the job.

“I don’t think about it,” he said. “I have an interest in getting through the next week. Speaker’s the kind of thing where lightning strikes. You can’t plan for it. You can’t campaign for it.”

Asked about the dinners with his colleagues, Mr. Brodsky said: “I’ve been going to dinner now for years.” He said he organized the dinners to thank those who supported his bid for comptroller.

Mr. Brodsky said his criticism of Mr. Spitzer is consistent with the independent positions he has taken over the years. He also said Mr. Spitzer’s administration is a significant improvement over Mr. Pataki’s.

“I am a strong supporter of the work by and large that Eliot has done,” Mr. Brodsky said. “He has brought enormous intelligence, energy, and focus to a lot of things that need intelligence, energy, and focus.”