Jeff Sessions on Tuesday challenged Tommy Tuberville to a series of five debates ahead of their July runoff in the Republican primary for U.S. Senate.

“It is time for you to stop running away, and face me and the voters of Alabama,” Sessions wrote in the challenge to Tuberville.

Sessions is trying to reclaim the seat he had held for 20 years before resigning to become President Donald Trump’s attorney general. Sessions was later forced out of the post after his relationship with Trump soured over Sessions’ recusal in the investigation into Russian interference in Trump’s 2016 election.

Tuberville led Sessions during the March Republican primary and the two face off again in the July 14 runoff.

Sessions said any potential Republican nominee must be able to demonstrate that they have a knowledge of the issues and suggested that Tuberville is not ready to take on incumbent Sen. Doug Jones in November or to represent Alabama in the Senate.

“And anyone representing Alabama needs to be fully vetted before they are trusted to represent Alabama Republicans in a race against Doug Jones,” Sessions wrote.

Tuberville dismissed the challenge

“If coaching taught me anything, it’s that you don’t let the losing team dictate the game when you’re sitting on a lead,” Tuberville said.

Tuberville has made Trump’s criticisms of Sessions a focal point of his campaign.

Tuberville, referencing Sessions’ recent social media exchanges with Trump, said that “Sessions seems like he already has his hands full debating President Trump on Twitter.”

Sessions defended his recusal in a tweeted exchange with Trump over the weekend.

“Look, I know your anger, but recusal was required by law. I did my duty & you’re damn fortunate I did. It protected the rule of law & resulted in your exoneration,” Sessions tweeted in response to Trump.