BBC news chief pleads with staff not to Tweet about 'our problems' Victoria Derbyshire, the Radio 5 Live presenter, said Mr Entwistle had "finally" resigned, while Norman Smith, the BBC's chief political correspondent, tweeted that Helen Boaden, who Ms Unsworth is relieving while an internal inquiry is carried out, would not go "without a fight" if the BBC tried to sack her. Ms Unsworth stressed her appointment "is a temporary one" and suggested Ms Boaden and her deputy Steve Mitchell would be back in their posts once Nick Pollard, the former head of Sky News, had concluded his review into why Newsnight cancelled a film last year that would have exposed Jimmy Savile as a paedophile. She said: "This is a tough time for everyone in the organisation - in particular for those of us in BBC News. And, of course, for some individuals most of all. Both Helen and Steve are outstanding leaders of BBC News whose experience and ability will be much missed in the coming weeks. Many of you have today shown a great deal of support for them and they wanted me to let you know how grateful they are for that. Mr Mitchell's job is being carried out by Ceri Thomas, while Karen O'Connor, an executive in BBC Vision, is acting as Newsnight's editor. Ms Unsworth continued: "Ceri, Karen and I do not undertake our newduties lightly. We would rather events had not worked out this way, but with our colleagues on the News Group Board, we will collectively do our very best to lead the division through these difficult times. We are relying on the support of all of you to achieve this. For the moment, we must focus on what matters most; delivering great journalism for all of our audiences. I have been enormously proud of the way you have gone about your jobs in your usual professional way, particularly over the past 48 hours. We now need to restore some equilibrium to the organisation.