Defusing an awkward leadership showdown, state Senator Karen E. Spilka announced she will take over as Senate president from the chamber’s current leader, Harriette L. Chandler, at the end of July.

The declaration appears to end weeks of behind-the-scenes negotiations and cringe-worthy public displays of tension between Chandler, who had hoped to serve as president until the end of the legislative session in January 2019, and Spilka, who announced last month she had the votes to be the next president.

“We have both shared a strong belief that our guiding priority must be to ensure stability in the Massachusetts Senate,” said the Democratic senators in a joint statement. “We have agreed that the transition between our tenures will take place the week of July 23rd.”


Chandler, for her part, said, “I am pleased to be handing the Senate over to a strong leader who will continue to lead us into the future.”

But the timing of the hand-off is unusual. Late July of an election year is when the Legislature is typically in a frenzy to wrap up business before formal sessions finish at the end of the month.

Until now, Spilka had been coy about when she might move to take the gavel from Chandler, who was elevated to the Senate’s top post after Senator Stanley C. Rosenberg stepped down from the presidency in December amid allegations his husband had sexually assaulted multiple men.

Chandler served as acting Senate president until February, when her colleagues decided to remove “acting” from her title, an attempt to end intense political jockeying for the presidency. At the time, Chandler said she would serve as leader until early January 2019.

But that changed after Spilka announced she had corralled the votes to be the next president.

Spilka, of Ashland, said in her Thursday statement that she has asked Chandler, a Worcester resident, to stay on as a “valued member of my leadership team.” But Spilka did not specify the role.


Chandler was previously the chamber’s majority leader before ascending to the presidency, but she put Senator Cynthia S. Creem in that role.

“I do not anticipate any significant changes in the Senate organization this year,” Spilka said.

The apparent end to tumult over the presidency comes a week after a statewide grand jury indicted Bryon Hefner, Rosenberg’s husband, on multiple charges of sexual assault, criminal lewdness, and distributing nude photographs without consent.

Last year, alleged victims told the Globe that Hefner had boasted of his influence on Beacon Hill and that they were reluctant to report his assaults for fear of alienating his powerful husband and harming their careers. Two have said they are among the four victims cited in last week’s indictment.

The Senate leadership drama began last fall, days after the Globe made public the allegations against Hefner. Rosenberg stepped down from the presidency, Chandler took the gavel, and the Senate initiated an investigation into the conduct of Rosenberg and whether he had violated Senate rules.

That investigation, being conducted by the Senate Committee on Ethics and an outside law firm, is expected to be completed in the coming weeks, with the results made public.

Meanwhile, senators expressed relief that a succession plan has been announced.

Senator Anne M. Gobi, a Spencer Democrat, said the transition date “makes sense” for several reasons.


“It gets us through the bulk of session, there’s no more guessing of when something is going to happen,” she said of the transition. “The budget itself will be finished [by then]. We’re all sort of used to the craziness at the end of session anyway.”

Gobi said Chandler should be applauded for stepping up to fill the presidency and guide the 40-member body in recent months. “I give her a lot of credit,” she said.

Governor Charlie Baker said he hopes the agreement will bring some “predictability” to the chamber and make it easier for the Senate — and the building as a whole — to pass a laundry list of legislation before the session ends.

He pointed to bills addressing opioid addiction, coastal resiliency and the budget as just a few of his priorities.

“This has obviously been a source of some distraction for people in the building and I think having this resolved will be a good thing,” Baker said. “We’re down to less than 100 days at this point, and the clock’s ticking.”

Joshua Miller can be reached at joshua.miller@globe.com. Matt Stout can be reached at matt.stout@globe.com.