RICHMOND, Va. (AP) — Virginia House Speaker Kirk Cox is backing a plan to have a bipartisan commission draw new legislative boundaries, a major shift in the yearslong fight over redistricting.

The Republican speaker said Monday that lengthy federal court battles over the 2011 redistricting lines have prompted him to back the formation of a commission. Democratic-led lawsuits led to a federal court redrawing the state’s congressional map and could lead to a new state House map.

Cox said he’s backing a proposed constitutional amendment that still gives the legislature a major stake in the process but would potentially limit future legal challenges.

“Your hope would be that you wouldn’t have Democrats systematically filing lawsuits,” Cox said.

Under this plan, lawmakers in both chambers and the governor would appoint a 12-person commission evenly split among Republicans and Democrats. The commission would present the legislature with new maps for the House, state Senate and congressional districts during redistricting, with the next one set in 2021.

If the legislature rejects the map, the commission could make alterations and present it again. If lawmakers reject it a second time, the Virginia Supreme Court would decide the final boundaries.

Democrats have capitalized on voter antipathy with President Donald Trump to score major wins in the last two election cycles, and could take control of the General Assembly after elections in November if the trend holds. With Democratic Gov. Ralph Northam in office, that would put Democrats in complete control of the next redistricting.

Last week, a panel of federal judges chose a new redistricting state House map that could shift some districts toward Democrats and help the party regain control in this year’s election. The judges ordered a new map after ruling that lawmakers had racially gerrymandered 11 House districts by packing black voters into them.

The judges are set to finalize a new map shortly. But the U.S. Supreme Court has agreed to hear an appeal of the case some time this year.

Cox said his support for a redistricting commission after opposing similar plans in the past was not motivated by his party’s political prospects.

“I’ve said all along I think we’re going to be in control of the legislature; I fully believe that,” Cox said.

Cox’s plan would have to pass the General Assembly this year and next year to become law.

Democrats, and a number of Republicans, have long supported independent redistricting commissions in the past. But it’s unclear if they will support Cox’s plan.

Redistricting reform advocates said they were troubled by a provision in the speaker’s proposal that directs the commission to try and “preserve the political parity” between Democrats and Republicans based on past election results.

Anna Scholl, executive director of the liberal group Progress Virginia, said Cox’s proposal is a step forward but falls short of a “transparent process where voters get to choose their elected officials, not the other way around.”