Four Republican state senators are calling for a special session of the General Assembly to address voting concerns before the January runoff — an idea that top Georgia leaders have already rejected.

In a statement released late Tuesday, the senators called for the session to “address structural issues with our voting system before the January runoff.” They also want the session to address “any evidence of voter fraud” brought to lawmakers.

The senators calling for a special session are Brandon Beach of Alpharetta, Greg Dolezal of Cumming, Burt Jones of Jackson and William Ligon of Brunswick.

Gov. Brian Kemp, Lt. Gov. Geoff Duncan and House Speaker David Ralston have already rejected calls for a special session, which costs taxpayers $40,000 to $50,000 a day. The General Assembly begins its regular session a few days after the runoff.

“Any changes to Georgia’s election laws made in a special session will not have any impact on an ongoing election and would only result in endless litigation,” the three Republicans said in a statement two weeks ago. Kemp did not address the issue in comments about the election Tuesday.

The calls for a special session come as some Republicans continue to cast doubt on the integrity of Georgia’s election system. Earlier this month, Republican U.S. Sens. Kelly Loeffler and David Perdue called on Republican Secretary of State Brad Raffensperger to resign because of unspecified problems for which they provided no evidence.

Both senators now find themselves facing stiff challenges from Democrats in races that will determine which party controls the chamber.

Raffensperger’s office has defended the conduct of the election, saying there is no evidence of widespread fraud or other irregularities, despite complaints by supporters of President Donald Trump, who lost Georgia to Democrat Joe Biden.

The secretary of state has called for a photo identification requirement for absentee ballots and other changes he says would strengthen the election system.

Raffensperger and Kemp also have raised alarms about partisans moving to Georgia temporarily to vote in the January runoff, though it’s unclear whether that is actually happening. Both have warned of stiff penalties if anyone is caught doing so.