North Carolina's incoming Democratic governor sued Friday over a new law passed by Republican legislators to limit his powers as he prepares to take office.

In his lawsuit, Gov.-elect Roy Cooper asks a Wake County judge to block a law that ends the control governors exert over statewide and county election boards from taking effect Sunday, when he'll be sworn in.

The lawsuit says the Republican-led legislature's radical changes two weeks ago to the administration of election laws are unconstitutional because they violate separation of powers.

The changes convert the state elections board from one that governors have controlled into a bipartisan body with equal numbers of Republicans and Democrats. County election boards would have two members from each party, rather than the current three members with a majority from the governor's party.

On Friday afternoon, a judge was hearing arguments by lawyers representing Cooper who are seeking an emergency ruling to halt the law from taking effect.

In a statement, Cooper argued that the new law could create longer lines at polling places, less early voting and general difficulty for voters.

"This complex new law passed in just two days by the Republican legislature is unconstitutional and anything but bipartisan," he said. "A tie on a partisan vote would accomplish what many Republicans want: making it harder for North Carolinians to vote."

But the Republican leader in the state Senate, Phil Berger, released a statement saying Cooper was trying to preserve his own power, not do what's best for voters.

"Given the recent weeks-long uncertainty surrounding his own election, the governor-elect should understand better than anyone why North Carolinians deserve a system they can trust will settle election outcomes fairly and without the taint of partisanship," he said.

Cooper's lawsuit makes good on his previous threats to take Republicans to court over laws passed during two December special sessions. Another of the laws requires Cooper's Cabinet choices to be confirmed by legislators. The state constitution gives the Senate the ability to "advise and consent" to the governor's appointees by a majority vote, but that provision hadn't been used in at least several decades.

Cooper won the November election against outgoing Republican Gov. Pat McCrory by about 10,000 votes. The transition was made bumpier by a protracted debate over vote-counting. McCrory didn't concede until a month after the election.