Boris Johnson's former chief adviser, Lord Udny-Lister, could go back to work for the Prime Minister and oversee the hiring of a senior adviser who can bring order to a chaotic Downing Street.

       Lord Udny-Lister – who as Eddie Lister was a trusted confidante of Mr Johnson's for 13 years in City Hall and later in Downing Street – quit as the PM's chief strategic adviser earlier this year.

       However, he has told friends he is willing to return to Number 10 to help find a senior figure who can help impose some discipline on both Mr Johnson and the team around him.

       One source said: "Eddie could go back in there and find somebody. Boris needs someone who can go in there and say: 'You can't do that.'"

       The news came as Mr Johnson's popularity dropped to an all-time low, with a net favourability rating of -42 – down 11 points since mid-November. The net favourability rating of Rishi Sunak, the Chancellor – widely seen as Mr Johnson's likely successor – was unmoved at -3, according to the YouGov poll.

       Mr Johnson strengthened the team of loyalists around him this summer when he brought Ben Gascoigne, his former private secretary, back into his inner circle. Mr Gascoigne was given the role of attending the 8.30am meeting and then touring government departments to enforce Mr Johnson's will.

       However, senior figures who have known the Prime Minister for years agree he needs a senior adviser to work cheek by jowl with him.

       One candidate for the "enforcer" role being suggested by Conservative MPs is David Canzini, a former senior figure in Central Office who has known Mr Johnson for 20 years.

       One Tory MP said: "He was part of Boris's 2019 campaign. He is respected across the party and would not stand for any nonsense, wherever it came from. If David were asked to help, he would help. He is known to ministers. He is a f------ hard man. He can provide advice in a very direct way.

       "There is a gap between the Prime Minister and the parliamentary party – so you would have someone who understands the party and the PM."

       ‘Loyal to his vision’

       Other names being suggested include Nikki da Costa, a former adviser on legislative affairs, and Will Walden, who handled Mr Johnson's public image when he was in City Hall.

       Another insider said the new senior adviser had to be someone with a keen political instinct, adding: "People around the PM have forgotten it is all about politics. It is fixable."

       Friends of Mr Johnson said he needed to clear out those in his senior team considered too close to Michael Gove, the Levelling Up Secretary.

       One said on Friday: "I don't think he is being well served with advice", while a second said MPs needed to be reminded that Mr Johnson was an "election winner" and added: "He needs people who are loyal to him and his vision."

       Lord Udny-Lister and Mr Canzini were unavailable for comment.

       Number 10 revealed it had cancelled this year's staff party, despite Mr Johnson's insistence that Christmas events should go ahead, "following the decision on Plan B and the latest data that we've got".

       It came after Rishi Sunak, the Chancellor, cancelled planned Christmas drinks with journalists on Monday, blaming "recent government updates to the working from home guidance, and given the business nature of the event".

       Sir Keir Starmer, the Labour leader, also cancelled his drinks for political journalists, scheduled for the middle of next week.

       Simon Case, the Cabinet Secretary and Britain’s most senior civil servant, has launched an investigation, although government sources and MPs are privately sceptical about any success, after his previous inquiry into the “Chatty Rat” Downing Street leaker ended in failure.

       “Who else is there to do it?” one Tory MP asked. “It should be the Cabinet Secretary who does it. The fact that he’s not a very good Cabinet Secretary, I suppose, is neither here nor there.”

       On Friday night, the BBC reported that Jack Doyle, Boris Johnson's Director of Communications, offered his resignation to the Prime Minister after it was revealed he had attended a Downing Street Christmas party, but had the offer rejected.

       No 10 said it was not true Mr Doyle had offered to resign and that Mr Johnson had full confidence in him.

       Although Allegra Stratton, Mr Johnson's former official spokesman quit over the row earlier this week, it is thought that Mr Doyle may have been granted a stay of execution until the conclusion of Mr Case’s investigation.

       On Friday, Mark Spencer, the Government chief whip, insisted in a rare broadcast interview that Downing Street staff “were not drinking alcohol” at the party and suggested Mr Johnson may not have known about it because there are “hundreds and hundreds of offices and rooms”.

       He told BBC Radio Nottinghamshire: “I'm assured that everybody in that building played by the rules, and that's why the Prime Minister has asked the Cabinet Secretary to do a thorough investigation to find out and establish the facts.”

       Asked how the Prime Minister might not be aware of what was happening elsewhere in the building given he lived in a flat next door, above 11 Downing St, Mr Spencer said: “When you describe it as a house, it's a department of government, this is a huge, huge building, literally with hundreds and hundreds of offices and rooms. No single person could account for what's happening in those buildings.”

       Lord Geidt, Mr Johnson’s ethics adviser, is also considering his position after it appeared he had been misled when writing a report about the refurbishment of the Downing Street flat last year.

       Downing Street said officials were “liaising with Lord Geidt to answer any further questions he may have” about the renovations.