Legislative staff have waited around four months to learn whether Senate President Karen Spilka would recognize their unionization effort with IBEW Local 2222, and on Thursday Spilka seemed to shut the door on that possibility — with an invitation for staff to attend a briefing from Senate lawyers on Friday.

Senators were cloistered in a lengthy private caucus Thursday afternoon in the Senate Reading Room, and Sen. Michael Moore posted a photo on Twitter of himself, Sen. John Keenan, and Sen. Sonia Chang-Diaz — supporters of the union push — in the Reading Room wearing State House Employee Union / Local 2222 lapel pins.

"Employees deserve to have a voice at their workplace, and we will keep fighting until every worker has that opportunity - including right here in the State House," Moore wrote alongside the photo.

Spilka addressed senators and staff in a 5:34 p.m. email, declaring "the Senate does not at this time see a path forward" for legislative staff unionization following "an exhaustive review" on "this complex legal area."

"With the information [Counsel] have provided to Senators today, the Senate does not at this time see a path forward for a traditional employer-union relationship in the Senate as we are currently structured," Spilka wrote in the email, which was obtained by the News Service.

The Ashland Democrat did not elaborate in her email on what, if any, structural changes she thought would make union recognition possible. A spokeswoman did not immediately respond to an inquiry on that subject.

Spilka added in her email, "I remain committed to making the Senate a great place to serve the people of the Commonwealth while building a career. We will continue our efforts to improve working conditions, benefits, and salaries, and we will incorporate staff input as we have done throughout my tenure."

A member of the State House Employee Union group told the News Service that a formal statement was still being developed in response to Spilka's message.

The union push inside the State House has riled the Legislature, where the ruling Democrats often express their support for the ability of employees to join unions and collectively bargain over wages and benefits.

Sens. Mike Rush and Brendan Crighton, the chair and vice chair of the Senate Personnel and Administration Committee, unveiled a plan in June under which all Senate staff would see at least a 10 percent bump in pay by the end of July.

The union push dates back to March 31, when IBEW representatives delivered a letter to Spilka's office seeking voluntary recognition.

On June 29, frustrated aides rallied on the State House front steps escalating their call for a response from the Senate president.

At that time, around 30 percent of senators were listed as publicly supporting the union effort: Sens. Sonia Chang-Diaz, Diana DiZoglio, Jamie Eldridge, Paul Feeney, Anne Gobi, Adam Hinds, Pat Jehlen, John Keenan, Eric Lesser, Michael Moore, Patrick O'Connor, Becca Rausch, and Walter Timilty.

In her email, Spilka invited aides to hear Senate Counsel "discuss their review" on Friday at 3 p.m. in the Reading Room.

"Any staff interested in learning more should plan to attend this in-person meeting," the president wrote.