Downfall completed with email, then a hug

Tony Blair appeared to have no idea what was coming when David Blunkett walked into his study at around 3pm yesterday. Mr Blunkett slipped into Downing Street using a hidden passage from the Cabinet Office to keep their meeting secret.

He was also keeping a secret from the Prime Minister, one that he had been sweating over for 24 hours. It was the existence of a "killer email" that proved a UK visa was, after all, fast-tracked for his ex-lover's nanny - and, much worse, implicated the Home Secretary in having triggered it.

"I think we have no choice but to find a way forward that does not embarrass you and the Government," he told Mr Blair. His words could only meanthat he would quit. The two men hugged briefly and Mr Blunkett was gone.

Mr Blunkett was told on Tuesday about the existence of the email by Sir Alan Budd, the head of the inquiry into "nannygate". He slept on it, then decided it was best not to bother Mr Blair before Prime Minister's Questions.

In fact, it looks likely that Mr Blair had more than an inkling of what was coming. For hours, the bongo drums around Whitehall had been beating the same tune, that Blunkett was on the way out. Outside Downing Street, news vendors were crying out the Evening Standard headline that there had been a collapse in Cabinet support for him.

One minister says an emergency meeting was held at No 10 yesterday morning, involving the Prime Minister's chief of staff Jonathan Powell and his head of government relations, Lady Morgan. The darkening mood was palpable. "There is a definite change in the air," said one senior MP during the afternoon. "It looks like he is reaching the end." Events unfolded slowly at first, then gathered speed. On Monday night, Mr Blunkett was so confident that he sang "Pick Yourself Up" at a karaoke party for Labour MPs.

On Tuesday morning Mr Blunkett seemed rattled when he left his London home. By now the walls were crumbling around him. First was a sudden sea change in. the attitudes of Cabinet ministers

A number, including several friends, confided that they no longer believed he could survive. The biggest cause was not the visa allegation at all, but resentment over the comments made by the minister about his Cabinet colleagues to his biographer.

A senior insider said: "Dealing with the book was not easy but there was still support. What ended it was the fact that this new information (the email) came up about the visa claims."

The email was damning. Written by a civil servant, it asked for nanny Leoncia Casalme's visa application to be hurried through the system. It made clear that a letter warning her of a nine-month delay had somehow found its way into the minister's overnight bag, thus bringing the case to the attention of officials.

One implication was that Mr Blunkett, or someone close to him, had inserted the document into the official papers to ensure the application was sped through the system. Neither Mr Blunkett nor his officials remembers how it happened. Mr Blunkett's final Commons outing as Home Secretary was to sit through question time and hear Michael Howard's taunts about his remarks on the Cabinet. "It's the Pollard book," Jack Straw was seen to whisper in his ear as Mr Howard produced a copy of the biography to Tory jeers. Mr Blunkett's face was a picture of misery.

Two hours later he set off to No 10 to resign. Events then moved at breathtaking speed.

By 5.20pm, the resignation had leaked. But it was announced, in classic new Labour style, at 6pm to coincide with the early evening news. Within an hour, Mr Blair announced a full list of Cabinet changes, working with breathtaking speed to tie up the loose ends.