Former Vice President Mike Pence says he will not be backing Donald Trump in the 2024 election.

“It should come as no surprise that I will not be endorsing Donald Trump this year,” Mr Pence said in an interview with Fox News Channel on Friday, commenting publicly for the first time since the former president became the presumptive Republican nominee.

Mr Pence ran against Mr Trump for their party’s nomination but dropped his bid before voting began last year.

The decision makes Mr Pence the latest in a series of senior Trump administration officials who have declined to endorse their former boss’s bid to return to the Oval Office.

While Republican members of Congress and other GOP officials have largely rallied behind Mr Trump, a vocal minority has continued to oppose his bid.

It also marks the end of a metamorphosis for Mr Pence, who had long been seen as one of Mr Trump’s most loyal defenders but broke with his two-time running mate by refusing to go along with Mr Trump’s unconstitutional scheme to try to remain in power after losing the 2020 election.

When Mr Trump’s supporters stormed the Capitol on January 6 2021 trying to disrupt the certification of Joe Biden’s win, Mr Pence was forced to flee to a Senate loading dock as rioters chanted “Hang Mike Pence!” outside.

In order to participate in the Republican primary debates, Mr Pence was required to sign a pledge saying that he would support the party’s eventual nominee. And during the first debate in Milwaukee, Mr Pence was among the candidates who raised their hands when asked whether they would support Mr Trump even if he were convicted in one of his four criminal indictments.

But Mr Pence had made clear he had come to harbour serious reservations about Mr Trump’s actions and his policy stances.

“I believe anyone that puts themselves over the Constitution should never be president of the United States and anyone who asks someone else to put them over the Constitution should never be president of the United States again,” he said during his campaign launch speech.

As the campaign progressed, he raised alarms about the party’s resistance to sending aid to Ukraine and called on his fellow Republicans to reject what he called the “siren song of populism” espoused by Mr Trump and his followers.

In the Fox interview, Mr Pence said he was “incredibly proud” of his and Mr Trump’s record in office, but said: “During my presidential campaign I made it clear that there were profound differences between me and President Trump on a range of issues, and not just our difference on my Constitutional duties that I exercised on January the 6.”

“I mean, as I have watched his candidacy unfold, I’ve seen him walking away from our commitment to confronting the national debt. I’ve seen him starting to shy away from a commitment to the sanctity of human life,” he went on, also referencing what he called Mr Trump’s “reversal on getting tough on China and supporting our administration’s effort to force” the sale of the popular TikTok app.

“In each of these cases, Donald Trump is pursuing and articulating an agenda that is at odds with the conservative agenda that we governed on during our four years. And that’s why I cannot in conscience endorse Donald Trump in this campaign,” he said.

Mr Pence declined to say whom he would be voting for — “I’m going to keep my vote to myself,” he said — but made clear it would not be Joe Biden.

“I would never vote for Joe Biden,” he said. “I’m a Republican.”