Wednesday, 26 February, 2003, 21:59 GMT
Prime Minister Tony Blair has just suffered the biggest rebellion from his own MPs since coming to power in 1997.
Blair's backbench rebellions
An estimated 122 Labour MPs backed an amendment to a motion saying the case for war with Iraq had not been proven.
Even though the amendment was not carried, this was far bigger than previous backbench rebellions:
9 January 2003 About 45 backbenchers rebel over plans to give top-rated NHS trusts more independence. The motion is still backed by 282 votes to 150.
7 February 2002 Again, an estimated 45 rebels vote against plans to promote further faith schools in England. But ministers still secure an overwhelming majority, helped by Conservative support.
22 November 2001 More than 30 Labour MPs vote against the government on controversial anti-terror measures. The measures still go through.
16 July 2001 More than 100 Labour backbenchers rebel over the attempted removal of two Labour MPs from the chairmanship of important parliamentary committees.
Gwyneth Dunwoody and Donald Anderson, from the Transport and Foreign Affairs Select Committees, are subsequently reinstated.
The affair is reported as Mr Blair's first Commons defeat.
24 October 2001 A small but interesting rebellion - three Labour MPs back the sacking of spin doctor Jo Moore, who had suggested in an e-mail sent on 11 September that the US terror attacks made it a good time to "bury" bad news stories.
She is saved in the Commons, but resigns about four months later.
16 November 2000 A rebellion by 37 Labour MPs over plans to privatise the national air traffic control service (Nats) is beaten by a government majority of 93.
5 April 2000 The government suffers a series of rebellions over its controversial Freedom of Information Bill.
The bill clears the Commons in the early hours - despite five backbench revolts involving up to 36 Labour MPs.
4 April 2000 Just the day before, 41 Labour MPs vote against plans to increase the basic state pension by just 75p. The vote goes through with a government majority of 165.
3 November 1999 The government suffers its second serious Commons rebellion over changes to incapacity benefit. But the rebellion is not as big as expected, weighing in at just 53, and the move goes through.
20 May 1999 65 Labour MPs vote against proposed changes to incapacity benefit, reducing the government's majority to just 40 - a Parliamentary whisker.
8 June 1998 In a surprisingly large revolt over government plans to abolish student grants and impose tuition fees, 31 MPs vote against the government - another 15 or so abstain. The government still has a majority of 137.
11 December 1997 Mr Blair's first major rebellion - 47 backbenchers oppose his plans to cut benefits to single parents.
Some 100 abstain, one minister and two Private Parliamentary Secretaries resign their posts, and a ministerial aide is sacked.
But because of Labour's large majority in the House of Commons, the government still managed to win all votes comfortably.