Suella Braverman has been forced to resign as UK home secretary, throwing Liz Truss’s premiership into further chaos and angering the Tory right. The Guardian was first to reveal that Braverman was departing, and that Grant Shapps, the former transport secretary who strongly backed Rishi Sunak in the Conservative leadership race, was replacing her. Braverman, a leading rightwinger, was sacked by the prime minister because she sent an official document from her personal email to a fellow MP, in a serious breach of ministerial rules. The draft written statement on migration was deemed highly sensitive because it related to immigration rules, which potentially have major implications for market-sensitive growth forecasts from the Office for Budget Responsibility. However, Braverman’s departure is a further serious blow to Truss’s authority, coming as a growing number of Tory MPs – including her net zero tsar – threatened to rebel in a fracking vote, she U-turned once again on the pensions triple lock, and she suffered a mauling from Keir Starmer at prime minister’s questions. Shapps’s appointment raised eyebrows in Westminster as he was believed to have been involved in attempts to get rid of the prime minister. It comes two days after he told Matt Forde’s podcast that he thought Truss was unlikely to survive. “She needs to thread the eye of a needle with the lights off, it’s that difficult,” he said. Braverman, in a brutal resignation letter that contrasted her actions with those of Truss, wrote: “Pretending we haven’t made mistakes, carrying on as if everyone can’t see that we have made them, and hoping that things will magically come right is not serious politics. I have made a mistake; I accept responsibility; I resign. “It is obvious to everyone that we are going through a tumultuous time. I have concerns about the direction of this government. Not only have we broken key pledges that were promised to our voters, but I have had serious concerns about this government’s commitment to honouring manifesto commitments.” In her perfunctory reply, Truss told her former home secretary: “I accept your resignation and respect the decision you have made.” Truss, still reeling from the massive blow to her authority dealt by Kwasi Kwarteng’s sacking as chancellor and his replacement, Jeremy Hunt, subsequently ripping up her economic strategy, had cleared her diary and called off a planned visit amid the fallout. She spoke to Braverman in her Commons office, according to insiders. Downing Street sources claimed the move was at the behest of Hunt, who has taken over control of the government’s economic response after Truss’s disastrous mini-budget, and who they claimed was now “pulling the strings”. The security breach was met with raised eyebrows from some of Braverman’s backers. Steve Baker, who co-led her leadership campaign and is now a Northern Ireland minister, said the use of a personal email had only been “technically” a breach of rules, and that such liaison with other MPs on policy was “perfectly normal”. One Tory MP said it seemed “very minor” and that most cabinet ministers had been guilty of the same thing. Another admitted: “If they wanted to keep her and she wanted to stay, this wouldn’t be a resigning matter.” A former No 10 aide also said it was “bullshit” that she would have been told to stand down for sending a draft written ministerial statement. “Special advisers and ministers, including the PM, have done much much worse,” they said. “Team Truss obviously handed her the revolver.” Braverman was an outspoken critic of Truss’s U-turn on the top rate of tax, suggesting she thought the prime minister had fallen victim to a “coup” earlier this month. Some Tory MPs on the libertarian right of the party have been left dismayed by the prime minister’s subsequent moves to ditch other tax cuts. Braverman’s departure comes after the Home Office passed a major piece of legislation, the Public Order Act. An ally who spoke to her earlier this week said she had been “upbeat”. Replacing Braverman with Shapps, less than a week after sacking Kwarteng as chancellor, is another sign of Truss trying to appeal to a broader section of the Conservative party and replace perceived ideologues with more experienced ministers. Braverman, who was given the job when Truss entered No 10 in early September, was seen as a backbench and party member-pleasing choice for the role, given her robust views on immigration, law and order and culture war issues. However, the former attorney general has been at the centre of several controversies since taking over, including after speaking out against a proposed trade deal with India due to her worries about it increasing migration to the UK. Braverman also pledged to reduce net migration to the UK to tens of thousands a year, a target promised before and generally found to be impossible to achieve. On Tuesday, Braverman used a debate on environmental protests to blame a “coalition of chaos” including opposition parties and the “Guardian-reading, tofu-eating wokerati” for supporting groups such as Just Stop Oil. Braverman has also sought to limit the number of international student visas, a lucrative income source for UK universities, while No 10 swiftly hosed down her suggestion that cannabis could be made a class A drug. With a tenure of 43 days, Braverman is the shortest-serving home secretary since the Duke of Wellington lasted just a month in November and December 1834. Her only modern rival for brevity in the role was Donald Somervell, who spent two months in the job in 1945 as part of Winston Churchill’s end-of-war caretaker government. In a point of order in the Commons, Yvette Cooper, the shadow home secretary, said: “This Tory government is falling apart at the seams. To appoint and then sack both your home secretary and chancellor within six weeks is utter chaos. This is no way to run a government. “Suella Braverman has admitted breaching security procedures, which raises serious questions. There are also reports of major disputes about policy and we have had weeks of disagreements. We need an urgent statement from the prime minister. Home affairs, security and public safety are too important for this kind of chaos. “The problems go beyond one home secretary. If the Conservatives can’t even manage the basics, they need to get out of the way and hand over to people who can.”