It has been a great honour to serve the House as Speaker for more than eight years

Betty Boothroyd

She also announced that she would step down as MP for West Bromwich West, meaning a by-election. She had a 15,423 majority at the last election, when she was not opposed by the Conservatives or Liberal Democrats.

At the end of her statement, Miss Boothroyd said: "Be happy for me!" to a spontaneous round of applause - a sound rarely heard in the House of Commons where clapping is regarded as "unparliamentary behaviour".

Miss Boothroyd explained to MPs that she was standing down after the summer recess this year to give her successor a "good run-in" before the general election.

"It has been a great honour to serve the House as Speaker for more than eight years," she told MPs.

Miss Boothroyd was elected Speaker in 1992 at the age of 62, after serving for five years as a deputy. She was the first woman to take the office.

'Deep regret'

Leader of the House Margaret Beckett responded to the announcement by saying MPs had heard Miss Boothroyd's statement with "deep regret", but told her the whole House "took pride and pleasure in your Speakership".

Gwyneth Dunwoody: Friend and possible successor

Ms Beckett explained that Ms Boothroyd would remain as Speaker during the summer recess, fulfilling outstanding engagements, but would stand down on 20 October just before parliament resumed.

The first day of business will then be given over to electing a successor.

Several MPs are being seen as candidates for the job, including Liberal Democrats Menzies Campbell and Alan Beith.

Gwyneth Dunwoody is being seen as the Labour frontrunner while Tory Deputy Speaker Sir Alan Haselhurst also has a number of supporters.

MPs are given a free vote on the Speaker, but it is likely government whips will exert pressure on backbenchers to vote for Mr Blair's choice, whoever that should be.