Metropolitan Police Commissioner Sir Paul Stephenson has resigned following the phone hacking scandal.
Britain’s most senior police officer has faced criticism for hiring former News of the World executive Neil Wallis – who was questioned by police investigating hacking – as an adviser.
Sir Paul said his links to the journalist could hamper investigations.
He said there were lessons to be learned from the affair, but he was leaving with his integrity intact.
He also said he had no knowledge of the extent of the phone hacking.
Home Secretary Theresa May said she was “sorry” he had resigned and thanked him for all the work he had done during his time in office.
She said: “Sir Paul has led the force through difficult times and although current circumstances show that there are still serious issues to be addressed, I believe that the force is operationally stronger today now than it was when he took over.”
Earlier, she said she would address MPs on Monday about her “concerns” over the closeness of the relationship between News International and police.
Sir Paul said in a statement: “I have taken this decision as a consequence of the ongoing speculation and accusations relating to the Met’s links with News International at a senior level and in particular in relation to Mr Neil Wallis.”
He added: “Let me state clearly, I and the people who know me, know that my integrity is completely intact.
“I may wish we had done some things differently, but I will not lose sleep over my personal integrity.”
It is expected that Sir Paul’s deputy Tim Godwin will take charge of the Met with almost immediate effect, before a more formal appointment process takes place.
Prime Minister David Cameron said Sir Paul had enjoyed “a long and distinguished career in the police”.
He added: “While I know that today must be a very sad occasion for him, I respect and understand his decision to leave the Met, and I wish him well for the future.
“What matters most of all now is that the Metropolitan Police and the Metropolitan Police Authority do everything possible to ensure the investigations into phone hacking and alleged police corruption proceed with all speed, with full public confidence and with all the necessary leadership and resources to bring them to an effective conclusion.”
