Andrew Mitchell's fate was decided by an alliance of Tory MPs from the 2010 intake in what is being dubbed as the "battle of the tea room", The Independent on Sunday can reveal.
The Chief Whip was forced to resign on Friday after four weeks of clinging on over his rant at police officers when he was warned he did not carry authority over the increasingly powerful cohort of independent-minded new MPs.
Witnesses to the turbulent scenes in the Commons tea room and the 1922 Committee meeting last week said the majority of the 148 MPs elected to Westminster two years ago "signed his death warrant" by draining support from the Chief Whip. One senior figure said Mr Mitchell had "completely misunderstood" the ferocity of "the 2010", as they are referred to in Westminster. "They hit as a pack," one MP said.
The group, making up about half the Tory parliamentary party, was instrumental in Mr Mitchell's decision to resign over "plebgate". He made the decision on Thursday, before formally offering his resignation to David Cameron on Friday.
Last Tuesday, the Sutton Coldfield MP entered the tea room, a lounge out of bounds to all but MPs, to try to smooth-talk his colleagues. "He was trying to be charming, but was given the cold shoulder," said one. At the same time, John Randall, the Tory Deputy Chief Whip, was telling MPs that Mr Mitchell had damaged the interests of the party and that he would resign if the Chief Whip did not. "There was blood on the carpet," said an MP. "It was clear then he wouldn't last the week."
Another senior figure said: "Mr Mitchell's last experience of the Whips' Office was during the mid-1990s, when he was trying – often without success, during votes on the Maastricht Treaty – to get Tory MPs to back the Government. But today's Tory party is a very different beast. He had a complete misunderstanding of the 2010 intake. They are dangerous, like no other intake that has gone before.
"His authority was shot. He had no authority with backbenchers. They have not come through the party system. They look to their constituency much more than the central party and the whips. A lot of them have got good careers that they could easily go back to if they chose to. They will not be coerced."
On Wednesday, Mr Mitchell tried to brave it out when Ed Miliband called him "toast" during Prime Minister's Questions. But some Tory MPs were aghast at reports that the Chief Whip had denied swearing – when he had earlier admitted he had. After PMQs, Mr Cameron summoned Mr Randall – who, despite a private education, had more of the "sergeant" than the "officer" about him, to use Mr Mitchell's description of Tory whips – to Downing Street to persuade him not to resign. The MP for Uxbridge agreed not to go there and then, but remained unhappy. At that evening's meeting of the 1922 Committee, five MPs spoke out against Mr Mitchell, but more were privately expressing dismay that the Chief Whip had not gone. One of the five who spoke up was Sarah Wollaston, the GP who was selected as Tory candidate for the 2010 election through open primaries – an indication of how independent the new MPs are.
Those who saw Mr Mitchell at close quarters on Thursday morning said it was clear he was under "enormous strain". Having lost, reportedly, a stone in weight and anxious about the toll the row was taking on his family, Mr Mitchell realised he had to resign when MPs failedto come forward to express their support. He took the decision on Thursday evening, and arranged with the Prime Minister's officials to set up a meeting at Chequers at 4pm on Friday, as soon as Mr Cameron had returned from Brussels.
Before MPs had returned to Westminster last week, Mr Mitchell had received about 70 messages of support from his parliamentary colleagues, but, because he had stayed away from party conference in Birmingham, he was blind to what the majority of backbenchers thought. A friend said: "He sounded out a lot of people in the parliamentary party on Wednesday and Thursday, and came to the conclusion that there wasn't enough support for him to do his job and cannot be Chief Whip. The 2010 intake were particularly aerated, at the '22 and in the tea room. He realised something: a lot of people were supporting him but too many weren't. You can't tell these things when you're not in Westminster."
Mr Mitchell spent about two hours at Chequers on Friday before a statement was issued by Downing Street shortly after 6pm. Mr Cameron accepted his resignation immediately, and did not try to dissuade him.
A No 10 source said: "The PM had already made clear it was completely unacceptable and had publicly admonished him. He apologised to the police officer and the police officer accepted that apology. But Andrew came to the conclusion that he couldn't carry on with the job."
Another friend said it was "excruciating" to watch Mr Mitchell's refusal to resign over four weeks. "It is very sad to watch someone who is the only person who believes they should stay in the job." Among those ministers who believed he should go was the Work and Pensions Secretary, Iain Duncan Smith, who, as Tory leader in 2003, blamed Mr Mitchell for plotting against him. Another was the Home Secretary, Theresa May.
Mr Mitchell was spending the weekend with his family. A friend added: "You don't get to be Chief Whip in this party without being a robust character in the first place. He is determined to carry on as an effective Member of Parliament and look after his constituency. He will be able to ride through the storm personally. He is made of strong stuff.
"He fully acknowledges that it had reached the point where he couldn't go on. He is also conscious of the fact that any feelings of self-pity as far as he is concerned are outweighed by what his family are going through."
For Mr Cameron, the weekend was spent at Chequers trying to plot his way out of the mess left behind. The Prime Minister will try to get back on the front foot with a major speech tomorrow in which he will call for a "tough but intelligent" approach to crime. He will argue that cracking down on offenders does not mean ignoring their rehabilitation.
But Ed Miliband, the Labour leader, accused Mr Cameron of being a "weak and clueless" Prime Minister who had little grip on his government, party and country.
A ComRes poll for The Independent on Sunday shows that Labour's lead over the Tories has increased by four points since last month: they are on 41 per cent, nine points ahead of the Conservatives on 33 per cent. Worryingly for Mr Cameron, more people believe that the fact he went to Eton makes it harder for him to be a good PM for the whole country – an increase from 34 per cent in July to 38 per cent now.
Senior Westminster figures are now warning the Prime Minister to ignore the 2010 intake at his peril. They come from both right and left of the party, with backgrounds in both state and private education, but are all focused, professional and organised. The 301 and 2020 groups are the more "Cameroon" of the cohort and saw Mr Mitchell's rage against a police officer as a threat to the project of modernising the Conservative Party.
It is not clear whether Mr Mitchell's replacement, Sir George Young, like the PM an old Etonian, will be able to grasp the potency and danger of the 2010. There are possible Commons rebellions coming up on gay marriage, renewable energy and, as ever, on Europe – something that, as Mr Mitchell knows well, has not changed since the 1990s.
While we were all looking the other way
Andrew Mitchell's last service to the Government may have been that his resignation took the heat off George Osborne. It was that sort of week for David Cameron, as a series of difficult stories chased each other across the front pages. But they also managed to overshadow what should have been good news for an embattled leader.
Energy shambles: A wizard wheeze to stop Ed Miliband in his tracks, announcing plans to make energy companies put customers on the lowest tariff. Except, er, none of his team knew about it. And it probably won't work.
Rebekah Brooks: Cameron at his most magisterial. Meeting Chris Bryant's call for him to publish potentially "salacious and embarrassing" emails between him and News International high-ups including Rebekah Brooks, with the equivalent of "I'm not talking to you any more". But no denial.
MPs' expenses: The 20-odd MPs who have been letting out their homes while living elsewhere at taxpayers' expense aren't all Tories, but it has focused attention on the super new expenses system. And we know who introduced that, don't we?
Robathan snubs veterans: Defence Minister Andrew Robathan came up with an interesting way to take on arguments against government plans to axe the Royal Regiment of Fusiliers – try to get their veterans thrown out of Parliament for being "too noisy" during a debate.
Osborne's train journey: The millionaire in charge of the nation's finances sits in a first-class carriage with a standard-class ticket. His aides deny talk of an argument with a ticket-collector, but concede that he had to pay an extra £189 to travel apart from hoi polloi. All in this together, as long as it's at the front of the train.
Salmond becalmed: The week started with a significant Cameron triumph: forcing the Scottish First Minister to accept that his independence referendum would be a single question (though he later hit back). More impressive, he escaped Edinburgh without looking like a visiting leader.
McKinnon extradition blocked: He was only a hacker looking for evidence of UFOs, but Gary McKinnon's extradition to the US was blocked, allowing Home Secretary Theresa May to please both left and right and upset a Democrat president in one fell swoop.
Crime down: Mrs May's good week continued with the revelation that crime is falling – by 6 per cent in the past year alone – despite economic hardship and those, usually wearing blue uniforms, who told her that a decline in police numbers would have the opposite effect.
Inflation and borrowing down: A fall in inflation last month – to its lowest level for nearly three years – took most people by surprise, although Mr Osborne maintains it is all part of a grand plan the rest of us don't understand. Followed closely by news that UK public sector net borrowing was £12.8bn in September, down from £13.5bn in the same month last year. Gasps in the City; whatevers in the Treasury.
Unemployment down: Another surprise – the unexpected fall in unemployment and a rise in those in work gave unemployment minister Mark Hoban his big chance to crow about the Government's success – and to explain exactly who he is.
How it all unfolded
Monday 3 September Andrew Mitchell is appointed Chief Whip.
Friday 21 September He has angry confrontation with police officers on duty in Downing Street. The Sun reports he shouted "learn your f****** place" and called officers "plebs" after being stopped from cycling out through Downing Street's main gates. He later apologises for not treating the police with proper respect but denies using the language reported.
Saturday 22 September David Cameron is urged to "urgently" review evidence around Mr Mitchell's outburst, including CCTV footage, as police suggest that the Chief Whip came close to being arrested during the confrontation.
Monday 24 September The police log of the incident records the Chief Whip describing officers as "plebs". Mr Mitchell reiterates his regret, but denies using the words reported. The Cabinet Secretary, Sir Jeremy Heywood, rules out an inquiry.
Thursday 4 October The Chief Whip pulls out of the Tory conference.
Friday 12 October He meets police officers in his Sutton Coldfield constituency in an effort to draw a line under the dispute.
Wednesday 17 October David Cameron defends Mr Mitchell during PM's Questions – the first since the incident occurred. At the weekly meeting of the Tory backbench 1922 Committee at Westminster, five MPs are said to voice concerns about Mr Mitchell's position.
Friday 19 October Mr Mitchell quits as Chief Whip. In his resignation letter, he says it had become clear that "I will not be able to fulfil my duties as we would both wish".