Michael Martin: 'I will relinquish the office of Speaker on Sunday, 21st June'
Michael Martin has told MPs he intends to stand down, so becoming the first Commons Speaker to be effectively forced out of office for 300 years.
In a brief statement, he said he would step down on 21 June, with a successor set to be elected by MPs the next day.
Mr Martin, who will also step down as an MP, has faced criticism over his handling of the MP expenses issue.
He later announced a clampdown on MPs' expenses - with a £1,250 cap on mortgage interest and rent payments.
He was clapped and cheered by MPs as he announced emergency changes to the expenses system which have been agreed between the party leaders.
These include a ban on "flipping" of second homes and of using allowances to buy furniture and household goods - and a £1,250 a month cap on mortgage or rent on second homes, which will come down in future years.
He said all parties were now committed to accepting the recommendations of Sir Christopher Kelly's Committee on Standards in Public Life, provided they met certain tests.
He also announced proposals to "tighten up" the administration of the expenses system with a "reasonableness" test to block dubious claims.
On Monday, Mr Martin apologised for his role in events but gave no indication about when he would stand down - only to be challenged by a succession of MPs who asked for a debate on a motion of no confidence in him.
At a time when the Commons desperately needed leadership, he failed to lead
In his resignation statement, on Tuesday afternoon, which lasted just 35 seconds, Mr Martin said: "I have always felt that the House is at its best when it is united.
"In order that unity can be maintained, I have decided that I will relinquish office of Speaker on Sunday 21 June.
"This will allow the House to proceed to elect a new Speaker on Monday 22 June."
He finished by adding "that is all I have to say on this matter" before going on to ask for questions to Foreign Secretary David Miliband.
Mr Miliband said the House would respect his wishes and pay its tributes at "a later date".
But independent MP Bob Spink, who asked the first question, paid "the warmest possible tribute" to Mr Martin - to "hear hears" from MPs.
BBC political correspondent Iain Watson said sources had confirmed that a meeting took place between the prime minister and the Speaker on Monday night to discuss Mr Martin's future.
Additionally, meetings were arranged between allies of the prime minister and friends of Michael Martin and between the Speaker and the government's business managers.
Our correspondent said the prime minister was very keen not to be seen to be forcing Mr Martin from office. But the key message at these meetings was that government business managers would have to allow a motion of no confidence to be debated if it were signed by a large number of people.
At a news conference Mr Brown paid tribute to his "30 years of public service" - a record of which, he said, Mr Martin and his family could be proud.
Mr Martin's spokeswoman said he would stand down as MP for Glasgow North East on June 21, sparking a by-election in what has been considered a safe Labour seat.
Later in a written statement Commons leader Harriet Harman paid tribute to Mr Martin's "passionate commitment to the House" and said he had served "with distinction".
David Cameron: 'A new Speaker is a good start'
She said: "Michael Martin's resignation today as Speaker is an act of great generosity to the House of Commons that Members of Parliament from all parties will respect."
Labour MP Paul Flynn, who was among those who signed the no confidence motion, told the BBC it had been "painful" to see the Speaker forced out but it was inevitable.
But he added: "He had not recognised the seriousness of the situation and... made a disastrous situation even worse by his lack of penitence, by his aggressive attitude by his attempt to blame the whistleblowers."
Mr Martin's critics say he was the driving force behind repeated attempts by Commons authorities to block details of MPs' expenses from coming out under Freedom of Information legislation.
Removing Michael Martin is not the end, it is the beginning - a new Speaker has to be reformist, they need to be progressive
But his supporters say he has long been the victim of snobbery and has been made a scapegoat for a scandal that has affected all the main parties.
Meanwhile, in other events linked to the row over MPs' second homes expenses, the Metropolitan Police have said they will not investigate how details of claims came to be leaked to the Daily Telegraph.
A spokesman said it was likely the "public interest defence would be likely to prove a significant hurdle" to a criminal prosecution.
But he said officers from the Economic and Specialist Crime Command had met senior Crown Prosecution Service solicitors to discuss allegations some MPs had misused public money.
Gordon Brown has said no Labour MP who broke expenses rules would stand at the next election.
And former Conservative minister Douglas Hogg said he would stand down as an MP at the next general election.
He has already agreed to repay £2,200 - the cost of clearing a moat at his country estate - which had been on paperwork submitted to the Commons fees office in support of his claims.
Tory backbencher Douglas Carswell - who put forward the motion of no confidence in Mr Martin - said the Parliamentary system had fallen into disrepute with many MPs being seen as "parasites" over the expenses scandal.
But he told the BBC: "Removing Michael Martin is not the end, it is the beginning - a new Speaker has to be reformist, they need to be progressive."
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