The Weekly Standard editor said on Bloomberg Politics’ Masters in Politics podcast that Romney, who has been highly critical of presumptive Republican presidential nominee Donald Trump, is contemplating a third-party White House run. Kristol, one of the most prominent Republicans in the “Never Trump” camp, said that while Romney initially ruled out another presidential bid, he may be coming around to the idea.

“The real last chance here is with Mitt Romney, who has said ‘no’ but who I think is thinking seriously about it,” Kristol said. “He is a very serious person, he really knows that Trump should not be president of the United States. He strongly believes that Hillary Clinton should not be president of the United States.”

Reached via e-mail, a Romney spokesperson declined to comment on Kristol’s assertion.