Boris Johnson's top Downing Street spin doctor has quit after a bitter power struggle behind the scenes.
In a major blow for the prime minister, his director of communications Lee Cain has resigned, just hours after reports there were bitter arguments over a plan to make him Number 10's chief of staff. He will leave the role at the end of the year.
In a statement confirming his resignation, Lee Cain confirmed he had been asked to serve as chief of staff before quitting.
He said: "After careful consideration I have this evening resigned as No10 director of communications and will leave the post at the end of the year.
"It has been a privilege to work as an adviser for Mr Johnson for the last three years - being part of a team that helped him win the Tory leadership contest, secure the largest Conservative majority for three decades - and it was an honour to be asked to serve as the prime minister's chief of staff.
"I would like to thank all the team at No10 - including the many unsung and incredibly talented civil servants - for their hard work and support during the last 18 months.
"And most of all I would like to thank the prime minister for his loyalty and leadership.
"I have no doubt that under his Premiership the country will deliver on the promises made in the 2019 election campaign and build back better from the coronavirus pandemic."
Responding to the shock news of his loyal ally's resignation, Mr Johnson said: 'I want to thank Lee for his extraordinary service to the government over the last four years.
"He has been a true ally and friend and I am very glad that he will remain director of communications until the new year and to help restructure the operation. He will be much missed."
There was speculation Mr Johnson would appoint Mr Cain to the pivotal position after criticism from some Conservative MPs over how the government has handled a number of policy and COVID-related situations.
Senior member of the influential 1922 Committee of backbench MPs, Sir Geoffrey Clifton-Brown, said MPs needed somebody to "get hold of" in the seat of power.
Speaking during a visit to a Tesco distribution centre in south east London on Wednesday, Mr Johnson refused to be drawn on the reports.
"I have got lots of fantastic members of staff. As soon as there is any further announcements to be made about that you will be hearing in due course," he said.
Former journalist Mr Cain was a prominent member of the Vote Leave campaign during the 2016 EU membership referendum.
Mr Cain worked with Mr Johnson when he was foreign secretary and was involved in his campaign to succeed Theresa May as prime minister.
The prime minister's chief adviser Dominic Cummings is reportedly not interested in obtaining the post of chief of staff.