Thirty dramatic hours that shook Westminster - and put Parliament back at the heart of the nation's affairs

The crisis engulfing the Government was underlined at Monday's emergency Cabinet meetingby the absence of Robin Cook, the Leader of the Commons, who had just resigned. His usual seat was occupied by Lord Goldsmith, the Attorney General, who is not a member of the Cabinet.

Mr Blair was not surprised by Mr Cook's departure. He had told Mr Blair last Thursday he would quit if Britain failed to win a new United Nations resolution on Iraq, a task the Prime Minister knew by then would be almost impossible.

On Friday, Mr Cook met Alastair Campbell, Mr Blair's director of communications and strategy, to discuss the handling of his departure. They agreed that it would be "amicable", and over the weekend even exchanged draft letters, Mr Cook's formal resignation and Mr Blair's reply, which were handed to reporters outside Downing Street at 4.30pm on Monday.

It was a very New Labour resignation. Mr Campbell's part in this choreography was strange; in 1997, he was the man who gave Mr Cook half an hour to choose between his wife and mistress while he was at Heathrow airport.

The feeling of surprise around the cabinet table on Monday was not that Mr Cook was absent but that Clare Short was there at all. Eight days after her stinging personal attack on Mr Blair's "reckless" strategy on Iraq, the Secretary of State for International Development opened the discussion by admitting: "I owe people an explanation." She went on, in her typically forthright fashion, to turn her fire on the French government, saying it had in effect "disabled" the UN by saying it would veto a new resolution.

She welcomed concessions Mr Blair had wrung from President George Bush on the Middle East and the role of the United Nations in a post-war Iraq, and said she would "reflect overnight" on whether she would resign.

Although this statement baffled some fellow ministers, most left the meeting believing Ms Short would decide to stay. "After all, if she was going to go, why was she still there?" one minister said. "It was bizarre." Outside the Cabinet, Mr Blair and Gordon Brown, the Chancellor, a close ally of Ms Short, pleaded with her not to quit.

Mr Blair told the Cabinet that taking action against Saddam Hussein if he failed to meet tests agreed by the UN was "a leap too far for some countries" who would never accept an ultimatum. Blaming the French, he said: "An impasse is an impasse. A block is not conditional but absolute."

Cabinet sources said Mr Brown, whose instincts are not as pro-European as Mr Blair's, was happy to join the tirade against the French, saying they had made it impossible to reach agreement.Closing the meeting, John Prescott made a powerful plea for the Cabinet to rally behind Mr Blair. The Deputy Prime Minister said: "These are the big moments when governments are really tested. Everyone has to stand firm." There were signs that such pleas for loyalty were going down well with Labour MPs, with whips reporting some would-be rebels coming back onside because of the French government and the imminence of military action.

But the see-saw atmosphere changed again when Mr Cook rose to make his resignation speech in the Commons at 9.44pm. The now former leader of the Commons paraded his well-known skills as Labour's finest parliamentary performer. He was sandwiched between two former cabinet colleagues turned rebels, Chris Smith and Frank Dobson, who jokingly described Mr Cook as his "protégé".

The Commons was crowded and the atmosphere was electric. MPs of all parties listened with admiration as Mr Cook dismantled the case for war that had just been made by Jack Straw, his successor as Foreign Secretary. Mr Cook's aides watched with tearful eyes.

The most dramatic moment came at the end of his 12-minute speech. Labour and Liberal Democrat MPs burst into spontaneous applause, which rolled around the chamber and turned into an unprecedented standing ovation. It was a breach of parliamentary etiquette but the Speaker, Michael Martin, caught the mood, making only a half-hearted attempt to stop it.

Mr Straw and other ministers listened grim-faced on the front bench. MPs agreed afterwards that Mr Cook's farewell statement was the most explosive Commons occasion since Lord Howe of Aberavon mortally wounded Margaret Thatcher in his resignation speech in 1990.

Perhaps recalling how Mrs Thatcher had squirmed in full view of the TV cameras as Lord Howe plunged in the dagger, Mr Blair made sure he was not in the chamber for Mr Cook's statement.

The Prime Minister had been at Westminster, holding one-to-one sessions with potential rebels in his Commons room in a corridor behind the Speaker's chair. But by the time Mr Cook spoke, Mr Blair was back in Downing Street, making telephone calls to "other world leaders", his aides said.

In recognition of Mr Cook's potential impact on the back benches, ministers were not keen to attack him. Peter Hain, the Secretary of State for Wales and former Europe minister, praised his former boss for a "brilliant speech" yesterday, while making clear he strongly disagreed with him.

The Government, stung by the scale of last month's Labour rebellion over Iraq, left nothing to chance in the run-up to last night's critical Commons vote.

A battle plan was drawn up to focus on 170 potential rebels, who were telephoned by whips and the cabinet heavyweight most likely to win them round, before being offered a face-to-face meeting with Mr Blair. Lobbying Labour MPs is a task he normally leaves to others, such as John Prescott, who has been working the Commons tearooms hard in recent weeks.

But not everything went according to plan. Bill Clinton was mobilised to pen an article for yesterday's Guardian but, to the fury of Blair aides, the newspaper edited out the crucial words "and Labour MPs" from his plea for the British people to trust the Prime Minister.

There was more bad news early yesterday when Lord Hunt of Kings Heath, a Health minister, invited himself on to BBC Radio 4's Today programme and announced his resignation from the Government.

Downing Street was not best pleased, since it had not been tipped off in advance. "All the normal rules of politics have gone out of the window," moaned one Blair ally.

Mr Prescott showed the Government's fury, telling the same programme: "I don't know who Lord Hunt is, he is obviously a minister of Government ... I'm sorry for my ignorance." This angered the rebel MPs, and Downing Street was forced to stress Mr Blair's respect for the work of Lord Hunt and the other ministers who had resigned on an issue of conscience.

There was better news when the BBC rang Number 10 to say that Ms Short was to issue a statement saying she had decided to stay in the Cabinet. Her extraordinary statement said she remained "very critical" of the Government's handling of the Iraq crisis but had decided it would be "cowardly" to quit at this stage. Later, she said at one point she had started to draft her resignation statement.

But the see-saw swung back again when John Denham, a Home Office minister, announced he was leaving the Government because he could not support it in last night's vote.

He had been earmarked by Mr Blair for promotion to the Cabinet this summer and his departure saddened and surprised fellow ministers.

Mr Cook may have won a standing ovation on Monday night, but Mr Blair won warm applause from his backbenchers at a hastily arranged meeting of the Parliamentary Labour Party yesterday morning. The 75-minute meeting was so crowded several ministers who arrived late were forced to stay in the corridor outside committee room 14.

The mood was sombre and serious but MPs closed ranks behind the Prime Minister after an 18-minute speech outlining the case for war. "Now is the time to make a choice," Mr Blair said. "We have to make the right choice. We have to do it believing in it and make the best of the situation we find ourselves in."

Hugh Bayley, a former minister, and Barbara Follett indicated they had been swayed by Mr Blair. Many MPs nodded as Kevin Hughes, MP for Doncaster North, revealed that his son was with the Armed Forces in the Gulf and urged colleagues to back the troops. Not a single MP referred to either Mr Cook or Ms Short, neither of whom was present.

As Mr Blair opened the Commons debate at 12.35pm yesterday, his wife, Cherie, made a rare appearance in the public gallery, underlining the importance of the occasion. The question on everyone's lips was: would the Labour rebellion be bigger than the one by 121 MPs three weeks earlier. "We're not doing a Bruce Forsyth, saying it will be 'higher' or 'lower'," one Blair loyalist said.

The Prime Minister's powerful speech was judged by MPs as one of his best performances. He had scribbled it in longhand on an A4 notepad on Monday morning instead of relying on speechwriters. At the last minute, he added a peroration that made clear he would resign if the Commons failed to endorse a war. But the scale of the expected Labour revolt meant that he continued to hold one-to-one talks in his Commons room with MPs while the nine-and-a-half-hour debate continued.

As the result was announced in the Commons, both sides claimed a moral victory with one Government whip maintaining: "It's a good result – it could have been a damn sight worse." A senior minister put a similar gloss on the result. He insisted: "The so-called rebels have peaked and we have won a massive majority in the Commons for the policy."

But Labour dissidents said they were delighted the vote had increased despite the most ferocious arm-twisting effort by a Government in living memory. Some wavering backbenchers had meetings with four Cabinet Ministers in a day, while Tony Blair set up camp in the Commons tearoom. One rebel said: "There was a lot of tea and jobs on offer."

Alan Simpson, the MP for Nottingham South, said the anti-war campaign had passed a crucial milestone by capturing support of more than half the "non-payroll" Labour vote.

He said: "It certainly shows the Prime Minister, with only half a mandate for war."

However, Clare Short was uncharacteristically reticent after the vote. She walked past waiting reporters with her aide, Dennis Turner, telling him: "Let's run for it."