But Marr’s departure could also open the way for Andrew Neil to make his BBC return.

Neil quit the broadcaster to launch GB News, a move that proved ill-fated. Asked this week if he would rejoin the BBC, Neil said: “I have no idea. I would like to do something on the TV front – count this as a job application – because I don’t want GB News to be the full-stop in my broadcasting career.”

Marr, 62, is leaving his £340,000 BBC job to join Global radio, where he will present an “opinion-led” show on LBC and another programme on Classic FM. Both will feature political interviews.

The veteran presenter previously expressed his unhappiness with the BBC’s strict impartiality rules, saying it was “very frustrating” that he could not speak his mind on political issues.

Announcing his decision on Friday, Marr said: “After 21 years, I have decided to move on from the BBC. I leave behind many happy memories and wonderful colleagues. But from the New Year, I am moving to Global to write and present political and cultural shows, and to write for newspapers.

‘We wish him well’

“I think British politics and public life are going to go through an even more turbulent decade, and as I’ve said, I am keen to get my own voice back.

“I have been doing the Andrew Marr show every Sunday morning for 16 years now and that is probably more than enough time for anybody.”

Fran Unsworth, the BBC’s director of news and current affairs, praised Marr as “a fantastic presenter and interviewer, whose wisdom and skill will be a loss to our screens”.

Tim Davie, the director-general, said: “Andrew Marr has been a brilliant journalist and presenter during his time at the BBC. He leaves an unmatched legacy of outstanding political interviews and landmark programmes.

“We wish him well for the next chapter.”