Andy Coulson quits Downing Street over phone-hacking scandal
In a personal statement issued by Number 10, Mr Coulson said he was "proud" of his work with David Cameron and the coalition.
But he added: "Nothing is more important than the Government's task of getting this country back on its feet.
Advertisement
Hide AdAdvertisement
Hide Ad"Unfortunately continued coverage of events connected to my old job at the News of the World has made it difficult for me to give the 110 per cent needed in this role.
"I stand by what I've said about those events but when the spokesman needs a spokesman it's time to move on.
"I'll leave within the next few weeks and will do so wishing the Prime Minister, his family and his brilliant and dedicated team the very best for what I'm sure will be a long and successful future in Government."
Mr Cameron said in a statement: "I am very sorry that Andy Coulson has decided to resign as my director of communications, although I understand that the continuing pressures on him and his family mean that he feels compelled to do so.
"Andy has told me that the focus on him was impeding his ability to do his job and was starting to prove a distraction for the Government.
"During his time working for me, Andy has carried out his role with complete professionalism. He has been a brilliant member of my team and has thrown himself at the job with skill and dedication. He can be extremely proud of the role he has played, including for the last eight months in Government.
"I wish Andy all the very best for his future, which I am certain will be a successful one."