House Speaker Nancy Pelosi has agreed to allow both Democrats and Republicans equal subpoena power and has conceded to an even partisan split on the 9/11 style commission that would investigate the Jan. 6 attack on the U.S. Capitol, backtracking from an earlier proposal that would have allowed Democrats to appoint a majority of members, sources familiar with the matter said.

Pelosi briefed her leadership team about the new proposal Monday evening, according to sources familiar with the negotiations.

The talks had stalled after Republicans and Democrats were unable to agree on the makeup of the committee and its investigative scope. It’s still unclear whether Republicans have reviewed or accepted the offer, as disagreements remain over the scope of the panels investigative work.

Senate Minority Leader Mitch McConnell addressed the commission during a news conference on Tuesday, saying the commission “needs to be balanced” and its scope “broader than just January the 6th.”

In February, Pelosi shared proposed legislation to set up the panel with Republicans after seeking input from lawmakers, relevant committees and leaders of the 9/11 Commission, including former New Jersey GOP Gov. Tom Kean, Lee Hamilton – the former Democratic congressman from Indiana who served as co-chair and Tom Roemer, another former Democratic congressman.

In interviews with ABC News, Kean, Hamilton and Roemer said they told Pelosi a successful commission would require appointing members who can avoid the partisan fray, supplying them with adequate resources and providing enough time to investigate on their own timetable, rather than one laid out by Congress or the White House.

Roemer told ABC News at the time that having the ability to subpoena is key. “Subpoena power for both individuals and information is key. The commission having it form the get-go, triggered by a simple majority vote, that is the solution to getting access to people and information in the case.”