RICHMOND — Gov. Ralph Northam warned Tuesday he would veto a redistricting plan that Republicans in Virginia’s House of Delegates hope to approve this month.

The lawmakers are set to consider new legislative boundaries in response to a federal court’s ruling that 11 House of Delegates districts were racially gerrymandered.

House Speaker Kirk Cox ­(R-Colonial Heights) said earlier Tuesday that he would summon lawmakers on Oct. 21 to take up a plan passed out of committee on a party-line vote last week.

If the legislature fails to act by Oct. 30, judges at the U.S. District Court for the Eastern District of Virginia will handle the redistricting themselves.

“I am firmly against judicial overreach and allowing federal judges to draw the map,” Cox said Tuesday in a news release. “The bottom line is this is the constitutional responsibility of the legislature.”

A three-judge panel of the federal court ruled June 26 that 11 Virginia House districts were drawn in 2011 in a way that lessened the influence of black voters. The 11 districts are in Hampton Roads and greater Richmond.

House Democrats unveiled their redistricting plan in August, and Northam (D) convened the General Assembly on Aug. 30 to consider it.

Republicans responded by asking the court for a stay of the deadline, which was denied, and by appealing the decision to the U.S. Supreme Court. Cox said Tuesday that he is pursuing the appeal but also intends to meet the Oct. 30 deadline.

All 100 seats in the House are up for election next year, and control of the chamber hangs in the balance. Republican lawmakers, who have a 51-to-49 advantage in the House, brushed off the Democratic redistricting plan and eventually produced one of their own. Democrats called it a partisan scheme, and the legislature appeared deadlocked.

Last week, Del. S. Chris Jones (R-Suffolk) delivered a redistricting plan that included input from a handful of Democratic legislators in Hampton Roads. The House Privileges and Elections Committee approved that plan last week — but on a party-line vote, 11 to 10.

Northam has said he was disappointed in the committee’s failure to reach consensus and has called on the courts to handle the matter. The committee’s action last week “reinforced my belief that this partisan process should not continue,” Northam said Tuesday in a news release. “I must unequivocally state that I will veto [the measure] should it reach my desk.”

Northam added that he hopes the legislature will amend the state constitution to create a mechanism for nonpartisan redistricting.

Cox slammed Northam’s position, saying it “stands in contrast to several private discussions with House leaders.”

He accused Northam of “feigning interest” in a legislative solution and said the governor “wants federal judges appointed by President Obama . . . to deliver a Democratic majority in the House of Delegates.”

Cox said he would reevaluate whether to stick with the Oct. 21 session.

The General Assembly faced a similar predicament in 2015, when a federal court found three congressional districts unconstitutional. The legislature failed to come up with lines of its own, and the court redrew the districts instead.