Boris Johnson has ordered Dominic Cummings to leave Downing Street with immediate effect, in a dramatic end to a tumultuous era which leaves a void at the heart of Downing Street. Cummings and his ally Lee Cain – both ardent Brexiters blamed by MPs for a macho culture and a series of communications crises – were asked to step down on Friday instead of staying in place until Christmas. One source said the prime minister told Cummings to go following accusations he had briefed against Johnson. Special advisers were said to be delighted by his departure. The prime minister was immediately urged to appoint an MP as his permanent chief of staff to help heal deep divisions with backbenchers amid warnings that his parliamentary party risked becoming ungovernable. Sir Edward Lister, Johnson’s chief strategic adviser, would become interim chief of staff until there was a permanent appointment, No 10 said. Cummings and Cain will continue to work for Downing Street until mid-December, with one source saying Cummings would be “working from home for six weeks”. The turmoil comes in the middle of a pandemic whose official UK death toll surpassed 50,000 this week, and days from a looming Brexit deal deadline. On Friday morning it was confirmed that Cummings was planning to leave by the end of the year following a bitter row over his close ally Cain. Cain’s promotion from head of communications to chief of staff was blocked by Johnson’s fiancee, Carrie Symonds, and other staffers this week, leading him to quit. But soon after 5pm, government sources said Cummings had left his post with immediate effect following a discussion with the prime minister. He was filmed leaving through No 10’s famous black door brandishing a large cardboard storage box. His exit came after 16 months when Cummings rose to become perhaps the most high-profile and notorious adviser of recent times in UK politics. Five months ago Johnson was accused of wasting enormous political capital in refusing to sack Cummings for travelling from London to Durham in lockdown – as exclusively revealed by the Guardian and Daily Mirror – causing a headache for MPs who were bombarded with constituents’ angry protests. On Friday night backbench MPs said a full reset was now needed to get a handle on the government operation, which has been left in tatters less than a year after Johnson won a resounding victory in the general election. Sources close to Johnson’s new press secretary claimed the departure of two of the prime minister’s closest aides marked a fresh direction for Downing Street and a reset of its chaotic communications strategy. Allies of Allegra Stratton, the former ITV journalist and Treasury adviser who will be the face of government TV briefings, said she had fought “a lonely battle” against Cain before he quit on Wednesday. Stratton is understood to have objected to Cain’s approach, arguing he wanted to cut journalists out of proceedings, making the briefings “cosmetic and pointless”. A Whitehall source said: “Cummings was not planning to go in this abrupt manner, but he was planning to go [at some point]. He had made that clear to several people in No 10 over several months.” One former official echoed this: “I think it was always predictable that there would be a big bust-up and Dom would leave. He’s done that in most jobs he’s been in.” Grant Shapps, the transport secretary, said Cummings was leaving because both the mass testing programme and Brexit were “on the near-term horizon now”. He told Sky News: “He will be missed, but then again we’re moving into a different phase.” Conservative MPs have almost unanimously cheered the news, and are pressuring No 10 to use the departure to restructure Downing Street, with a well-respected and organised chief of staff at the heart of things. Sajid Javid, the former chancellor who quit in anger at Cummings, was being touted as a potential new chief of staff. “It has been made plain to the PM that there will have to be major changes,” one senior backbencher said. “I want to see an MP as chief of staff and a second-to-none political operation which stops walking into traps laid by Labour. We [also] need a parliamentary relations unit to transform relations with MPs.” However, a Labour source said: “The prime minister can rearrange the deckchairs in the Nasa-style command centre all he wants – the fact there is no plan and no focus in the government’s response to Covid is entirely down to him.” Another Tory backbencher said some new MPs had not had an opportunity to get to know Johnson or No 10 and were already beginning to abstain or vote against the government. “They have spiralled off into orbit, and if the party isn’t careful, they will become serial rebels, never to be seen again,” they said. “Because of coronavirus, they have not been able to attend parties and functions with the PM and see his good side. They need to be shown some love and attention by Boris, he has to let them know that he needs them on board, and show us all the old campaigning Boris instead of the new, tired, depressed Boris.” Theresa Villiers, the former environment secretary, welcomed what she called “a good opportunity for a fresh start”. She said: “Clearly there are concerns about the dismissive attitude sometimes shown by Lee Cain and Dominic Cummings towards people in government and MPs on the backbenches. This is an opportunity to move on from that and to have a more collaborative approach.” Sir Bernard Jenkin, the senior Tory backbencher who chairs the Commons liaison committee, which scrutinises the work of government, said there was a chance to restore “respect, integrity and trust” between No 10 and Tory MPs. “It’s an opportunity to reset how the government operates and to emphasise some values about what we want to project as a Conservative party in government,” he said. The exit of Cummings and Cain marks the end of an apparent internal hegemony of Vote Leave alumni and their supporters. There had been predictions that another key Downing Street adviser, Oliver Lewis, could also resign, and even Johnson’s chief Brexit negotiator, David Frost. But one ally said they did not expect any more departures: “I think people took a deep breath and decided to get on with it.” They said the atmosphere inside Downing Street had soured amid the intense pressures of Covid and Brexit: “These things would test the most stable of relationships. It’s a weird world where you’re basically arguing with each other via WhatsApps to journalists to print in newspapers, rather than just sitting in a room.” A number of Tory MPs have been openly scornful about the eruption of infighting during such a difficult period for the country, with the government beset by a series of policy U-turns. A YouGov poll earlier this week had Labour ahead by five points and Johnson’s approval ratings slumping, with 34% approving of his performance but 59% disapproving. One former adviser said Johnson faced a crucial decision about who to appoint as chief of staff: “The important thing is restoring a sense of order. Boris always outsources a sense of grip and direction to key lieutenants. Until we know who that is, it’s difficult to say how it will work.” But a former Downing Street staffer warned that MPs expecting a permanent shift towards more collaboration with backbenchers would be left disappointed. “The contempt for MPs does not come from Dominic Cummings,” they said, “he’s just a harder version of the smiling frontman. The basic contempt comes from Boris Johnson. This is not a guy who does the Commons tearooms, who fraternises with fellow MPs. This is a guy who gets blown around by whatever storm; he has no political compass. “Cummings was his ultimate human shield, the lightning conductor for all the hostility from Whitehall and politicians but it is Johnson’s leadership that is the problem. He is an outsider, a personality. There’s very little seen of him building a support base within the party.”