RICHMOND, Va. (AP) — Virginia Republicans asked state’s highest court Monday to block more than 200,000 felons from voting in November, arguing that Democratic Gov. Terry McAuliffe abused his power by restoring the voting rights of thousands of convicts who’ve completed their sentences.

In a lawsuit GOP leaders filed in the Virginia Supreme Court, they say McAuliffe violated the separation of powers by effectively suspending the state’s ban on voting by felons. They say McAuliffe is ignoring decades of practice, which has made clear that governors can restore voting rights only on a case-by-case basis.

“Gov. McAuliffe’s executive order defines the plain text of the Constitution, flouts the separation of powers, and has no precedent in the annals of Virginia history. The governor simply may not, with the stroke of the pen, unilaterally suspend and amend the Constitution,” their lawyers wrote in the suit.

The lawsuit is being brought by House Speaker William Howell and Senate Majority Leader Thomas Norment along with four other Virginia voters.

They’re asking the justices to prohibit election officials from registering felons and to cancel all such registrations since April 22. As of last week, election officials said nearly 4,000 felons had signed up to vote, media outlets reported.

McAuliffe’s administration has fiercely defended the action and says it’s confident the executive order will withstand the challenge. The governor says there’s nothing in Virginia’s Constitution that limits him to restoring rights only on an individualized basis and accused Republicans of trying to preserve “a policy of disenfranchisement” that has predominantly impacted African-Americans.

“These individuals have served their time and are now living, raising families and paying taxes in our communities — this suit is an effort to continue to treat them as second-class citizens,” McAuliffe said in a statement. “This is simply the latest Republican attack on the voting rights of qualified Virginians who deserve a voice in their society, and we will oppose it vigorously.”

The governor’s order entitles every Virginia felon to vote, to run for public office, to serve on a jury and to become a notary public upon the completion of his or her sentence and any supervised release, parole or probation requirements as of April 22. The administration estimates this population to include about 206,000 people.

GOP leaders said Monday that the governor’s action is already having potentially harmful unintended consequences, citing a recent Washington Post story that said it has made it easier for ex-felons to have their gun rights restored. Without having to go through the process of having their civil rights reinstated, felons who’ve finished their sentences can now go straight to a judge and ask for their gun rights back, the newspaper reported.

McAuliffe’s administration stresses that it would still ultimately be up to a judge to decide whether any felons should be allowed to carry a weapon.

Republicans expressed urgency in ensuring the court addresses the matter before November, but acknowledged there’s likely nothing they can do to prevent felons who’ve registered to vote from participating in the upcoming primary elections. On June 14, GOP candidates for Congress are facing off in the 2nd, 4th and 6th Districts. Democrats will also choose a general election candidate for the 4th District next month.