The announcement by Michael Martin that he intends to stand down comes at the end of several days which has seen growing criticism of Mr Martin's handling of the expenses row.

While details are to be confirmed during a statement to the House of Commons at 2.30, a number of MPs have already voiced their opinions over the latest development.

One Labour MP who directly called on him to go - David Winnick - has welcomed the move.

He said: "That is the right and honourable course to take. His resignation will be the first step in the House recovering its reputation."

Tory backbencher Douglas Carswell tabled the motion of no confidence in Speaker Martin.  He said it gave him no pleasure to have played a part in bringing Mr Martin down, but said the House of Commons needed a new Speaker to help guide it out of the current crisis.

The Harwich and Clacton MP told Sky News: "I have acted not as his enemy and least of all as an opposition MP. I have acted as somebody who cares passionately for the parliamentary system.

"I believe we have found ourselves in a moral ditch and we need reform and change to get out of that ditch and restore dignity to politics.

"It gives me no pleasure to have done this at all, but it was necessary to do it. We need a new Speaker who understands that 'sovereignty of Parliament' is shorthand for 'sovereignty of the people'.

"The reason why I think we need Michael Martin to step down is because he not only presided over this system, he actively sought to prevent reform."

Labour MP Paul Flynn, a signatory of the no-confidence motion, said Mr Martin had needed "this very sharp lesson from Parliament" to persuade him that he had to go.

"He just wasn't getting it, even up until yesterday," Mr Flynn told Sky News.

"He could have gone with a great deal more dignity last week if he had got the message. I'm afraid he has brought this on himself.

"Parliament has to reform itself and he was the wrong person to lead it."

Liberal Democrat Norman Baker - one of the MPs publicly rebuked by Mr Martin over his criticisms of the way the expenses issue had been handled - said it was the "right decision" for him to step aside.

"I am afraid that the Speaker and the House of Commons Commission which he chairs has been the main obstacle to reform," he told the BBC News channel.

"They have blocked reasonable requests for information, they have spent vast amounts of money on court action to stop information coming out, they even tried to exempt MPs from Freedom of Information altogether."

Mr Winnick said: "It was not his chairmanship of the Commons over the last nine years that was in question; it was his role as chairman of the House of Commons Commission that brought this about.

"The next Speaker, in my view, should in no way be involved in the House of Commons Commission. That is the path to disaster."

Labour backbencher Austin Mitchell said he was "saddened" that Mr Martin appeared to be being forced out at a time not of his choosing.

"It is tough justice," said Mr Mitchell. "He would probably have gone at the election anyway, but it now looks like a public humiliation.

"Clearly he has made a mess of the open government issue and our expenses, but in resisting publication he was doing what the House itself wanted. It's a shame now that he should carry the can.

"Partly it is a class issue - the Tories have never liked him. But the main issue is fees and allowances. There has been a hue and cry whipped up by the Daily Telegraph and the House of Commons has given in to it.

"We have thrown them a bone and God knows who is going to be next."

Labour former Cabinet minister Frank Dobson said he was "distressed and to some extent disgusted" at what was happening to Mr Martin, whose efforts to keep the expenses system secret were backed by most MPs at the time.

Mr Dobson told BBC News: "It is a bit like a lot of people in a lifeboat slinging one person out in the hope that the water won't now lap over us."

He added: "I think it is a dreadful example of the House of Commons as a whole - which as a whole is responsible for the mess we are in - trying to scapegoat one man who was trying to represent what he thought were their views on what should be done.

"Until about a fortnight ago, what he was trying to do did represent most members' views."