Democratic state lawmakers in New York acted with partisan intent and tried to restrict electoral competition when drawing congressional lines in violation of the state's constitutional ban on partisan redistricting, a five-judge court on Thursday ruled. 

The ruling gives lawmakers until the end of the month to draw new lines for the state's House districts. But New York Democrats are expected to appeal the decision, which also upheld the legality of the state legislative maps for the Assembly and state Senate, reversing a lower court's decision. 

The legal challenge to New York's congressional maps is now expected to head to the state Court of Appeals, New York's highest court.

The stakes for both parties are substantial given the coming House of Representatives elections this fall, and the push by Democrats nationally to maintain control of the chamber. 

New York, a heavily Democratic state, has been home to multiple battleground districts over the last decade. 

The ruling on Thursday was a mixed one. On the one hand, the court determined the state constitution "is silent" on how legislative boundaries should be drawn if an independent commission fails to reach an agreement for new maps for the state Legislature and House districts. 

The judges wrote that "the legislation used to fill the gap in that procedure is not unconstitutional and that the redistricting maps enacted by the legislature pursuant to that legislation are not void" going forward. 

But the lines themselves were drawn with a clear intent to favor Democrats, the court found, pointing to the testimony of redistricting expert Sean Trende. 

"We conclude that evidence of the largely one-party process used to enact the 2022 congressional map, a comparison of the 2022 congressional map to the 2012 congressional map, and the expert opinion and supporting analysis ... met petitioners’ burden of establishing that the 2022 congressional map was drawn to discourage competition and favor democrats in violation of" the state constitution, the judges wrote in the ruling.

The ruling partially upholds, and also narrows, a state Supreme Court judge's decision that rejected the congressonial maps. 

The case will move to New York's Court of Appeals, a seven-judge court appointed by two Democratic governors, Andrew Cuomo and Kathy Hochul. 

"We are pleased the Court upheld the legislature's process and the right for the legislature to enact these maps," said Mike Murphy, a spokesman for the Democratic conference in the state Senate. "The newly-drawn Senate and Assembly maps are now valid. We always knew this case would end at the Court of Appeals and look forward to being heard on our appeal to uphold the Congressional map as well."

Republicans have maintained since the maps were first approved earlier this year the lines were drawn to heavily favor Democratic candidates running for office this year. Democrats have rejected that claim, arguing the maps fairly reflect a Democratic-dominated state. 

“We are pleased that the Appellate Division confirmed what all New Yorkers know: The Congressional map that the Democrats in the Legislature adopted is an egregious, unconstitutional gerrymander," said Republican former Rep. John Faso, who is advising the plaintiffs in the case. 

Gerrymandering, a process in which voters are essentially picked by officials and drawn together to maximize the likelihood of electoral outcomes, has been decried by good-government organizations for hardening partisanship across the country.