Mitt Romney has said he will stand down from the Senate at the next election, as he called for politicians in their eighties to “move on” and argued the Republican Party has been captured by a “super MAGA” faction.

The Utah senator, 76, said he would not seek a second term in Congress after a career spanning three decades and two presidential bids.

Speaking to The Telegraph on Tuesday, Mr Romney criticised politicians still in office in their 80s, including Joe Biden and Nancy Pelosi, hit out at the “baby boomer generation” and called for the GOP to return to the moderate centre-Right.

The senator bemoaned the success of Donald Trump, who has been leading primary polls since he announced his candidacy in March, and pledged to focus on climate change and US debt in his remaining months in office.