Speaker Michael Martin faced direct calls for him to quit today over the Westminster expenses scandal but refused to give any indication if he would step down.
In extraordinary scenes in the Commons, Mr Martin said he was "profoundly sorry" for the public anger over MPs' expenses claims.
"We all bear a heavy responsibility for the terrible damage to the reputation of this House. We must do everything we possibly can to regain the trust and confidence of the people."
Mr Martin said he was calling an urgent meeting of all the party leaders to discuss proposals for reform.
But backbench anger over the Speaker's handling of the crisis swiftly erupted on the floor of the House as a series of MPs directly challenged his authority in points of order.
Labour's Gordon Prentice (Pendle), one of the signatories of the motion of no confidence in the Speaker, asked if it would be debated tomorrow and voted upon.
Mr Martin said this was not a point of order but was interrupted by Mr Prentice who insisted "Oh yes it is".
The Speaker continued: "These are matters for debate on an appropriate motion."
Tory Douglas Carswell, who tabled the no confidence motion earlier, demanded: "When will Members be allowed to choose a new speaker with the moral authority to clean up Westminster and the legitimacy to lift this House out of the mire?"
The Speaker initially said Mr Carswell's motion was an Early Day Motion and unlikely to be debated, telling the Tory: "Please give me credit for having some experience in the chair".
But following a series of interventions from MPs and clarification from the clerks, he said the motion would be listed in the "remaining orders" which could only be proceeded with if it became a substantive motion.
In response to Labour's David Winnick (Walsall N), Mr Martin refused to say whether he would step down before the next general election.
Mr Winnick said: "There is great public anger outside which undoubtedly has harmed the reputation of this House. We all bear responsibility, I take my share of responsibility like every other Honourable Member.
"But can I put this to you, and I'm not associated with the motion, Sir, would you bear in mind that it would be very useful to the reputation of this House - and I say this with reluctance, but I say it all the same - if you gave some indication of your own intention to retire. Your early retirement, Sir, would help the reputation of the House."
Mr Martin pointed out that the veteran MP would know "that's not a subject for today".
Mr Martin said that while the Commons awaited the report of the Committee on Standards in Public Life "we must search for agreement" so Commons Leader Harriet Harman could bring forward resolutions to deal with the issue.
"In the meantime I do urge all Members not to submit claims for approval."
The Speaker said he had last week held a "most productive" meeting with standards watchdog Sir Christopher Kelly, who said he hoped to bring proposals forward in the autumn on MPs' expenses and allowances.
"While we await the outcome of his work it is imperative that we continue to improve our accounts and practice in the interim and get in place measures that work and are seen to be working."
Michael Martin's statement came after a motion of no confidence in him was tabled by Tory MP Douglas Carswell, and signed by 15 MPs from the three major parties, after Liberal Democrat leader Nick Clegg urged him to resign.
Earlier today Gordon Brown declared that Michael Martin's fate was in the hands of MPs. The Prime Minister called for "root and branch reform" of the expenses system, but when invited to back Mr Martin said simply: "The decision on who is Speaker is a matter for the House of Commons."
Mr Brown has previously praised Mr Martin as doing a good job, but that formula has now been dropped both by the premier and his spokesman.
Mr Martin also faced the prospect of a motion of no confidence in him being tabled at Westminster and Mr Brown's spokesman said: "The Prime Minister and the Government will support the will of the House."
Speaking at an event in north London to mark the launch of the Government's car scrappage scheme, Mr Brown said: "The decision about who is Speaker is a matter for the House of Commons. It could never be a matter for the Government."
He added: "What we have seen in expenses and in the revelations has angered and appalled me. It has angered me because people expect politicians to be serving the public and not serving themselves. It has appalled me because I was brought up to believe that we must have the best standards in public life.
"So there has got to be fundamental change. We are no longer talking about papering over the cracks. We are no longer talking about a minor change here or there.
"There has got to be root-and-branch reform and I am hopeful that we can get a consensus in this country about what is needed to be done to have a complete clean-up of the political system and to make sure that people can have trust in what their politicians do.
"Some MPs are doing a very, very good job - indeed most of them are. But where there are faults, and where there are failings and where people are responsible, they have to accept that there will be disciplinary action.
"We will cut the expenditure on these items and at the same time we will have a wholesale root-and-branch reform of the system."