By Ollie Stone-Lee
Political reporter, BBC News website
It was dubbed the week from hell when the Conservatives last faced a struggle for the party leadership while holding a conference in Blackpool.
Macmillan's resignation shocked the conference
Forty years on, the Tories are about to do it all again.
At least this time the party has for months known it must choose a new leader.
In 1963, activists travelling to the conference on a Tuesday afternoon had no inkling that ill health was about to prompt Prime Minister Harold Macmillan's shock resignation.
Macmillan's illness was news even to ministers who had seen him in Cabinet that very morning.
Veteran political journalist Anthony Howard recalls how Conservative chairman Iain Macleod went to a dinner that evening thinking everything was going perfectly.
His secretary sent a message telling him his sister was ill, thinking he would understand its real meaning.
"I haven't got a sister, what's this rubbish," was Macleod's confused reaction before they managed to drag him away from the dinner.
Anthony Howard witnessed Tory "mayhem"
The following night news of Macmillan's illness was relayed to Tory members.
But it was not until the Thursday of the conference that the dramatic news of the prime minister's resignation came, with Alec Douglas-Home announcing it to a shocked conference.
"From that moment on it was absolute mayhem..." says Anthony Howard. "In the hall they were just stunned."
As the news sank in, Lord Hailsham was the first to declare his hand.
That evening, Hailsham finished a lecture to Conservative activists by saying he intended to renounce his peerage so he could run for the leadership.
Geoffrey Howe, who was just starting the political career which would take him into the Cabinet, says Hailsham's announcement prompted a tremendous stranding ovation.
He remembers Anthony Howard sitting in a box alongside the stage acting as "cheerleader" for Hailsham - not because he was campaigning for his leadership, but because he was "campaigning for excitement".
"I fear the story is true," admits Mr Howard, saying the temptation to urge on the crowd proved too much.
They "went wild", he says, and for a brief time it looked like the wind was behind Hailsham.
Lord Hailsham: "The politics of the Nuremberg rally"?
Next morning he posed for the photographers holding a baby.
"That was considered very vulgar. He was really almost out of it by Friday," says Mr Howard.
John Biffen, then a backbench MP, says Hailsham's supporters did not need much encouragement to stand and clap at the lecture, although he refused to join them.
He dubbed the event "the politics of the Nuremberg rally" - although admits it was well-executed.
Lord Howe says Hailsham's speech had a double effect.
"One was to remind people what a great orator he was, the other to remind people who wanted to be so reminded that he was an impulsive chap who couldn't be trusted. It was a 50-50."
The issue dominated the conference, says Lord Howe: "It was all very exciting - I can't remember what influence we thought we had."
This was all in the days when there was no vote for the new Tory leader - they just "emerged" from soundings within the party.
That system meant much of the action happened back-stage, beyond the eyes of the ordinary party members at the conference.
In his memoirs, journalist and ex-Tory minister Bill Deedes says much of the talks happened in various bedrooms "much to the distress of wives".
"A wife would emerge unclad from the bathroom to find her husband, still in pyjamas, talking to three totally strange men in grey suits, who would go on talking," he says.
"Around the hour women like to dress up for cocktails, she would plead: 'I'm going to take my clothes off.' This would be ignored, such - we supposed - was the urgency of our consultations."
There were essentially four candidates - Douglas-Home, Butler, Hailsham and Reggie Maudling.
Douglas-Home's candidature surprised many, not least because he had told colleagues that very week he would not enter a future leadership contest.
Anthony Howard's abiding memory is standing beside Maudling watching Douglas-Home do a television interview.
Stunned by Douglas-Home's coded language, Maudling turned and said: "He wants it, he means to have it."
Butler's speech failed to wow the activists
Maudling's own chances suffered by a low-key speech which failed to generate a genuine standing ovation.
That left Butler trying to make his mark.
Dismissing the advice of his supporters, he had insisted on taking the prime ministerial hotel suite upon news of Macmillan's illness - as well as the leader's speech slot in the end of conference rally.
Hit by a heavy cold, his speech failed to wow the audience.
Butler biographer Anthony Howard believes Rab was unnerved by Douglas-Home telling him shortly before the speech that he was going to have a medical test - code for announcing his own candidature.
Bill Deedes contests that the speech did not seriously affect Butler's chances.
Douglas-Home only "emerged" as leader after the conference, with Macmillan giving the Queen his advice on his successor from his hospital bed.
Douglas-Home "emerged" as leader
The decision prompted Enoch Powell and Iain Macleod to resign from the government in protest.
But what lessons does 1963 hold for today's Tory hopefuls, who will after all face a vote?
Anthony Howard says that conference proved decisive: "It disposed of three candidates and left one standing - Alec Douglas- Home."
In the same way, the impression left by today's candidates could be similarly important, he says.
He asks: Will Ken Clarke produce a rumbustious performance; will David Cameron come across as too "wet" and can David Davis, the one with most at stake, make a presentable speech?
Lord Howe believes there are no direct lessons to be learnt but says it is sad that a conference that should be about the party's aims will be overshadowed by leadership implications being read into everything.
His former Cabinet colleague Lord Biffen warns that a party conference is about the worst institution to help choose a new leader.
"It does become something like a beauty contest," he says.
"Oratory is all very well and really we need quite a lot of it in politics. But for calm detached assessment of the relative qualities of people who are standing it is quite difficult to get that."
If he is right, the 1963 conference nightmare could prove 2005's recurring dream.