Representative Mo Brooks, who is running for Senate in Alabama, named senators Ted Cruz and Ron Johnson as two possible replacements for Senate GOP Leader Mitch McConnell.

Brooks, a loyal Trump ally who has received the endorsement of the former president, predicted there would be “significant resistance” to McConnell being the leader of the Senate while appearing on Mobile-based radio station 106.5.

He also named Senators Rand Paul of Kentucky, Mike Lee of Utah and Josh Hawley of Missouri as potential leaders he could support if elected—adding he would still support McConnell over a more moderate Republican.

“But, I’m going to vote for whoever is the most conservative person running for the leadership of the Republicans in the United States Senate,” he said.

He noted that he has concerns about whether or not McConnell would be able to work with former President Donald Trump, who continues to wield significant influence in the GOP.

The relationship between McConnell and Trump has become increasingly frayed in recent months, as the former president continues to attack the Kentucky senator. In December, he called McConnell the “best thing that ever happened to” Democrats.

McConnell also caught the ire of Trump after supporting President Joe Biden’s $1.2 trillion bipartisan infrastructure bill.

Brooks said he has “seen nothing to suggest that he is going to be able to work things out with Donald Trump.”

“But we’ll see how it plays out in that regard,” he added, also citing McConnell’s low approval rating as a reason the GOP needs a new leader.

“Keep in mind that if you look at the Real Clear Politics average of all of these people who are prominent in Washington, D.C., Mitch McConnell far and away has the worst unfavorable-favorable ratio,” he said. “We need someone who has more respect of the American people.”

Brooks has been a critic of McConnell as far back as 2017, when he called on him to resign after the GOP failed to repeal the Affordable Care Act.

He is seeking a Senate seat being vacated by Senator Richard Shelby. He has served in his Huntsville-based House district since 2011.

Polls show him as one of two candidates favored to enter a runoff—along with Katie Britt. In Alabama, a candidate has to win more than 50 percent, rather than a plurality, in an election. Whoever wins the primary would be the strong favorite in the general election, as Alabama is one of the most conservative states in the U.S.

Newsweek reached out to both McConnell’s office and Brooks’ campaign for comment Saturday evening. This story will be updated with any response.