The BBC's director general, George Entwistle, has resigned in the wake of the Newsnight child abuse broadcast.
In a statement given outside New Broadcasting House, Mr Entwistle said: "I have decided that the honourable thing to do is to step down."
Earlier, Mr Entwistle said the Newsnight report, which wrongly implicated ex-senior Tory Lord McAlpine should never have been broadcast.
The broadcast covered cases of child abuse at north Wales care homes.
Mr Entwistle took up the post of director general on 17 September.
In his statement, he said: "In the light of the fact that the director general is also the editor in chief and ultimately responsible for all content, and in the light of the unacceptable journalistic standards of the Newsnight film broadcast on Friday 2 November, I have decided that the honourable thing to do is to step down from the post of director general."'Great honour'
He said that when he was appointed to the role, he was confident BBC trustees had chosen the best candidate for the post and the "right person to tackle the challenges and opportunities ahead".