This story has been updated with a comment from Rep. Jeffrey Roy.

A FIGHT is brewing on Beacon Hill over the rules governing how joint committees made up of House and Senate members steer bills through the Legislature.

Sources say House chairs have been pressing their Senate counterparts to change the way the committees operate. For the most part, the discussions have taken place out of public view. But over the last several days the long-simmering power struggle emerged from the shadows during a series of email exchanges between the House and Senate chairs of the Legislature’s Joint Committee on Telecommunications, Utilities, and Energy and the scheduling of a hearing for this Thursday.

Rep. Jeffrey Roy of Franklin, the House chair of the committee, sent out an email to the panel’s members last Thursday seeking “an agreement of the majority” for a hearing schedule for the legislative session.

Twenty-one minutes later Sen. Michael Barrett of Lexington, the Senate chair of the committee, responded with an email of his own, accusing Roy of violating the Legislature’s joint rules by unilaterally attempting to schedule committee hearings. Barrett said the Legislature’s joint rules require both chairs to agree on a timetable for committee hearings. He urged his colleagues not to support Roy’s motion until rules governing committee deliberations are negotiated.

Barrett also took aim at Roy himself, sharing the gist of an earlier email exchange with the House leader. “The rules you inexplicably no longer like ensure equality between the branches,” Barrett wrote. “This discussion is ultimately about substance, not procedure. If the very idea of rules for our committee is suddenly out of fashion and the Senate loses its equal voice, I fear that the committee’s substantive results may be considerably less bold.  I worry that good climate policy would be at risk.”

Barrett’s reference to an “equal voice” is a nod to Senate concerns that without rules giving the Senate some leverage, a strict majority-rule approach in legislative committees would give the House control of the committee process.

Joint legislative committees are made up of lawmakers from both branches but, because of the difference in size between the two branches (160 members in the House and 40 in the Senate), House members typically outnumber their Senate counterparts on the committees by roughly a 2-1 margin.

On the Telecommunications, Utilities, and Energy joint committee, the House has 11 members and the Senate six. Not counting Republicans, the House has nine members and the Senate five.

The dispute between Barrett and Roy came to a head Monday morning when Roy sent out an official notice of the hearing this Thursday and listed Barrett as a co-sender of the invitation despite his opposition to holding the hearing. The hearing notice said Roy would chair the hearing.

“I’m listed as the co-sender today of an official joint committee hearing notice, along with the House chair. The House chair knows I haven’t approved the scheduling of this hearing. There’s a small chance this is merely a serious error. Otherwise, I regret to say, the use of my name appears to be fraudulent,” Barrett said.

“The misrepresentation aside, the House chair’s unilateral act, which I have to assume is the first of what will be others, violates the Joint Rules of the General Court approved by both branches earlier this year and viewable today on the Legislature’s website,” Barrett said.

Other Senate chairs are being pressed in similar fashion, Barrett said. “It’s almost as if the House is done with the delicate power-sharing that enables joint committees to work. It wants either to dominate the joint committees due to the House’s sheer numerical advantage or drive us towards the Congressional model, in which the House and Senate handle bills separately. Either way, this is quite a turn in the road.”

Barrett said he intends to ask Senate members of the committee to hold their own hearing on Friday. He said House members are welcome to take part in the Friday proceeding.

Roy issued a statement Monday afternoon that urged Senate members of the committee to come to the Thursday hearing, the first of the nearly five-month-old session. “The broader discussion on adoption of official committee rules should not prevent the committee from holding hearings on critical legislation,” he said. “As House chair of the Joint Committee on Telecommunications, Utilities, and Energy, I am advocating for committee rules that prevent one chair from maintaining absolute control over which bills are released from committee, a power that not only diminishes the influence of each individual member of the committee, but that was also wielded last session to delay the consideration of major energy legislation, and to block hundreds of other bills from advancing through the committee.”

The emerging power struggle on Beacon Hill between the two legislative branches echoes a similar fight that erupted in 2015 when Senate leaders threatened to scrap the joint committee system unless the House agreed to changes to the committee rules. The fight in 2015 eventually subsided and the following year the House and Senate reached compromise on a few rules changes.

The key difference this time is that the House speaker and Senate president appear to be staying out of the fray, at least publicly.

In 2015, then-Senate President Stanley Rosenberg threatened to blow up the joint committee structure and move to a system in use in most state legislatures and the US Congress, where each branch has its own committees. That approach eliminates friction at the committee level, but it also creates the potential for twice the number of hearings on bills.

Robert DeLeo, the speaker at the time, condemned Rosenberg’s tactics.

“The Senate’s proposal is an impolitic and manufactured reaction to a non-existent problem and is a significant distraction at a time when the Commonwealth is at a critical juncture,” DeLeo wrote in a Boston Globe commentary. “If committee members, whether senators or representatives, can’t convince a majority of their colleagues to support their bill, they should take a hard look at the policy they are promoting rather than blaming the process.”

Rep. Ron Mariano, who was the House majority leader in 2015 and is today the speaker, also took umbrage at Rosenberg’s willingness to speak out publicly rather than negotiating behind closed doors.

Neither Mariano nor Senate President Karen Spilka has said anything publicly about the rules negotiations going on in the various joint committees.