An appeals judge on Friday declined to slow down New York’s primary elections amid a battle over the state’s redistricting plan, but said he would allow a lower court judge to hire an expert to draw up alternative congressional district maps in case the disputed ones ultimately get tossed.

The ruling by state Appellate Division Justice Stephen K. Lindley essentially hands the decision about the constitutionality of the redistricting plan over to a higher court, while creating one possible contingency for keeping the elections on schedule.

The state board of elections can still accept petitions filed by candidates running for office in the new districts, Lindley's ruling said.

New York’s primary season was potentially upended last week when a Republican trial judge, Judge Patrick McAllister, declared that new political district maps heavily favoring Democrats had been drawn up illegally.

He ordered the Legislature to quickly redraw the district boundaries, or he would appoint a neutral expert to do it for them.

That ruling has been put on hold while the state appeals.

An appeals court panel has scheduled another hearing for April 20. The case could ultimately be decided by New York’s highest court, the Court of Appeals.

In his ruling Friday, Lindley said he would allow Judge McAllister to retain a neutral expert to draw up a new Congressional map, if he wishes to do so, to be used if the Legislature's maps are eventually struck down.

The legislature could also draw up a contingency map, if it desires, Lindley said.

“The Legislature may begin redrawing the map right now if it chooses to do so,” he said. “Or the Legislature may choose to do nothing and risk the possibility of having to live with the map drawn by Judge McAllister’s neutral experts should respondents lose before the Court of Appeals and lack sufficient time to propose a substitute map that withstands constitutional scrutiny after exhaustion of appellate remedies.”

Former GOP U.S. Rep. John Faso, a spokesperson for the plaintiffs, said they were pleased with the decision, which empowers the Steuben County judge to appoint a master to draw lines. “Ultimately the Court of Appeals will decide, but we’re very much encouraged by this decision today,” Faso said in an email.

Lawyers for the Senate and Assembly assured Judge Lindley on Thursday that the maps will pass constitutional muster.

Legislative leaders have said they don’t plan to redraw the maps, and defended them as reflecting population loss in former Republican upstate bastions.

Judge Lindley said Thursday that he was chiefly concerned about the prospect of allowing New York voters to pick candidates based on unconstitutional maps.

He said New York must be ready for the possibility of Congressional primaries delayed as late as August 23 or 24.

The state judge also struck down the Assembly and Senate maps on procedural grounds.

But Judge Lindley did not allow backup plans for legislative maps in his Friday order. He said there was “less need” for a court master to draw up new legislative maps because the lower court didn't find they were unconstitutionally gerrymandered.