Jeremy Paxman is to step down as a presenter of Newsnight, BBC2's flagship late-night politics show.
Paxman, who has appeared regularly on the programme for 25 years, decided to leave last summer, but then agreed to continue for another year to help Newsnight emerge from the aftermath of the Lord McAlpine scandal under new editor Ian Katz.
The last Paxman-fronted edition of Newsnight will air in June.
In what colleagues described as an "emotional" speech to them this afternoon, Paxman - who is to interview popular economist Thomas Piketty on tonight's programme - said it was "better to go at a time of my own choosing" but that "I have no idea what I am going to do next".
A press statement from Paxman added: "I have decided it is time to move on from Newsnight. After 25 years, I should rather like to go to bed at much the same time as most people. This was a decision I reached - and informed the BBC of - last July. I shall work out the remainder of my contract and will not seek another.
"It's been fun. I have had the pleasure of working with lots of clever, creative and amusing people. I think I've been lucky and wish the programme well."
Ian Katz said: "It’s been a huge privilege to work with Jeremy for the last eight months. I’m deeply grateful to him for delaying his departure to help renew the programme, and for the extraordinary support and generosity he has shown. We – and the viewers – will miss him greatly, but he leaves the show in good health and a formidable new team in place."
James Harding, the BBC's director of news and current affairs, commented: "Jeremy has led from the front: fearless, aggressive and persistent. He never failed to ask the difficult questions and always refused to accept glib or deceptive answers. Of course we will miss him but he has set standards for our journalism that the rest of us must follow.
“We accept his decision to move on but I think it is fair to say that the only people really celebrating his decision will be the politicians and public figures he has so often and so brilliantly held to account.”
The programme's diplomatic editor Mark Urban said: "I have worked with Paxman for more than 20 years on Newsnight. He is a genuine one-off, and quite irreplaceable.
"Quite a few people shed tears after Paxman's departure [was] announced," Urban added via Twitter. "A lot of people having trouble absorbing it. The end of an era."
Paxman will continue to present University Challenge for BBC2.