Following the terrorist attacks in the US, the announcement of the result has been postponed for 24 hours as a mark of respect and is now expected at 1615GMT/1715BST on Thursday 13 September. Live coverage of the result will be available here at BBC News Online
11 September 2001
Final votes cast
Both Iain Duncan Smith and Ken Clarke say they are confident of winning. But a series of surveys and polls suggest IDS, as he is known, is clear favorite and the bookmakers agree. But Conservative leadership elections are notoriously difficult to predict. The BBC's Carole Walker looks at the two men as the campaign comes to a close.
Iain Duncan Smith's campaign
Ken Clarke's campaign
30 August 2001
Clarke brands Smith too right-wing
In an increasingly bad tempered contest, Ken Clarke called his rival Iain Duncan Smith "a hanger and a flogger" in an interview with BBC Radio 2's Jimmy Young Show. Smith flatly rejected the label, saying he did not understand the concept of left- and right-wing.
The BBC's Nick Robinson reports
Listen to Ken Clarke on the Jimmy Young Show
Listen to Iain Duncan Smith on the Jimmy Young Show
28 August 2001
Smith denies extremist support
Iain Duncan Smith denied reports that he dropped Tory MP Andrew Hunter from his campaign because of links to the party's right-wing Monday Club, the day after he sought to establish a tolerant image with a newspaper article praising ethnic diversity.
The BBC's Nick Robinson reports
24 August 2001
Smith campaign in BNP row
Edgar Griffin, a member of Iain Duncan Smith's campaign team, was exposed for having links to the far-right British National Party and expelled from both the team and the Conservative party.
The BBC's Jonathan Beale reports
Edgar Griffin on the Today programme
22 August 2001
Europe dominates candidates' debate
In the only head-to-head debate of the leadership election, broadcast live on Newsnight and Radio 5 Live, Ken Clarke and Iain Duncan Smith clashed repeatedly on the issue of Europe.
Watch the whole Newsnight debate
Major backs Ken Clarke
Former Conservative Prime Minister, John Major has publicly backed Kenneth Clarke, saying he would give the Tories a better chance of regaining power. He also hit out at Lady Thatcher, accusing her of undermining him in office by encouraging backbenchers including Iain Duncan Smith to oppose his government's policy on Europe.
The BBC's Carolyn Quinn reports
John Major on the Today programme
21 August 2001
Lady Thatcher weighs in
In a letter to the Daily Telegraph, former Conservative Prime Minister Lady Thatcher threw her support behind Iain Duncan Smith and said Ken Clarke would steer the party to "disaster".
20 August 2001
The ballot begins
The two contenders set out their plans as ballots are sent out to party members. Kenneth Clarke and his rival, Iain Duncan Smith, have been permitted to send one mailshot each with the ballot papers and party members have three weeks to cast their votes.
Click below to see the manifesto launches.
Kenneth Clarke manifesto launch
Iain Duncan Smith manifesto launch
17 July 2001
Loser Portillo quits Tory frontline
Ken Clarke surprisingly tops the final round of the Tory MPs' leadership ballot with Iain Duncan Smith second, eliminating Michael Portillo. Speaking minutes after the result was announced Mr Portillo told BBC News: "I don't intend ever to be on the frontbench again and for the avoidance of doubt I'm not interested in the leadership."
The BBC's Mark Mardell reports
14 July 2001
Duncan Smith the new favourite
Shadow defence secretary Iain Duncan Smith has emerged as the favourite to succeed William Hague as Conservative Pary leader. Both his rivals, Michael Portillo and Ken Clarke, admit that the right-wing Mr Duncan Smith is likely to top the poll of Tory MPs when they vote on Tuesday.
13 July 2001
Davis quits Tory leadership race
David Davis has pulled out of the Tory leadership race. The decision came after he secured fourth place in the re-run first round of MPs votes in the contest, where he scored just one vote more than Michael Ancram who came last. As MPs faced a new wave of bids for their votes, Mr Davis announced he would now be backing Iain Duncan Smith.
The BBC's John Pienaar reports
David Davis talks to the BBC about his reasons for quitting
12 July 2001
Portillo ahead after first round proper
Michael Portillo won the re-run Tory leadership battle among MPs, with former party chairman Michael Ancram eliminated from the next round of voting after coming last.
The BBC's Mark Mardell reports
10 July 2001
First vote fails to convince
Michael Portillo wins a chaotic first ballot of Tory MPs for the party leadership - but a re-run was immediately ordered after two candidates, David Davis and Michael Ancram tied for last place. The BBC's Mark Mardell reports.
27 June 2001
Tories elect new 1922 chairman
Senior Conservative MP Sir Michael Spicer is elected by his colleagues to represent them as the new chairman of the 1922 committee. His first and most important task is to organise the party's complex process of choosing a new leader to replace William Hague.
26 June 2001
Clarke enters battle
Former Chancellor Ken Clarke says only he and Michael Portillo could win an election for the Tories, who must end their divisions over Europe. The BBC's Tim Finch reports
22 June 2001
Clarke's secret Tory leadership decision
Former chancellor Ken Clarke comes to a decision on whether to join the Conservative leadership race, but refuses to say what it is. The BBC's Mark Mardell reports
21 June 2001
Ancram enters Tory race
Michael Ancram announces that he is to run for the Tory leadership. He puts his name forward because so many people inside and outside parliament convinced him that he could not "stand aside" from the battle to be fought.
Click here to watch Michael Ancram's announcement
21 June 2001
Portillo launches manifesto
Michael Portillo sets out his personal manifesto for the Conservative Party's future. Speaking at his official campaign launch in London, he tells his audience of supporters: "We need to have the courage to make the change."
19 June 2001
Tory right join the fight
Two more Conservative MPs from the Eurosceptic right of the party formally launch their bids to succeed William Hague as Tory leader. Shadow defence secretary Iain Duncan Smith says the party needed to broaden its appeal. David Davis, the former Europe minister, says he wanted to build a modern Conservative Party ready to take office again.
Iain Duncan Smith launches his campaign
David Davis launches his campaign
The BBC's John Pienaar reports
18 June 2001
Widdecombe pulls out
Ann Widdecombe pulls out of the race to lead the Conservative Party. She delivers her announcement on an east London housing estate, saying she would be happy to serve under any of the contenders except Michael Portillo - whose close aides and allies she has previously denounced as "backbiters".
Click here to watch her statement: 56k
17 June 2001
Major praises Portillo
When the last Conservative prime minister John Major was caught on tape referring to the right-wing "bastards" in his cabinet, Michael Portillo was generally taken to be one of them. Now, though, Mr Major praises Mr Portillo for moving back to the centre of the party - although he stopped short of endorsing him.
Robin Chrystal reports
Click here to watch: 56k
John Major speaks to David Frost
Click here to watch: 56k
Click here for full transcript
14 June 2001
Clarke undecided
Former Conservative chancellor Ken Clarke says he still wants to be Tory leader but has yet to decide whether the party is ready to be led by a pro-European. Mr Clarke tells the BBC: "I would like to be leader of the Conservative Party and I have not given up my ambitions to be prime minister."
Mr. Clarke's statement
Click here to watch: 56k
13 June 2001
Portillo launches his bid
Michael Portillo announces his candidacy for the leadership stressing the need to build an inclusive Tory Party. Launching his bid, he says: "We need to adopt a tone that is moderate and understanding. We need to be talking about the issues that they [the public] are talking about."
Andrew Marr reports
Click here to watch: 56k
Michael Portillo's announcement in full
Click here to watch: 56k
11 June 2001
Portillo set to stand
After recuperating from the Conservative election defeat in Morocco, Michael Portillo returns amid confident predictions he will stand for leader. But already rivals are sharpening their knives. Right-winger Ann Widdecombe is canvassing for support while Ken Clarke, holder of the One Nation torch, is considering his position.
Martha Kearney reports.
Click here to watch: 56k