LONDON - The Speaker of Britain's lower house said Tuesday he would step down in June after criticism of his handling of a scandal over lawmakers' expenses that has badly tarnished the reputation of the Mother of Parliaments.

Michael Martin becomes the most senior figure to step down after parliamentarians' expense claims for everything from manure to porn films triggered outrage across recession-hit Britain and opposition calls for an early general election.

In order that unity can be maintained, I have decided that I will relinquish the office of Speaker Sunday, June 21, Martin said in a short statement to a packed parliament. A new Speaker will be elected the following day, he added.

The last Speaker to be forced from the post was John Trevor, who lost the confidence of the house in 1695 for taking a bribe.

The Speaker is parliament's most senior official and his departure escalates the crisis engulfing British politics.

Martin has been criticized for opposing transparency on expense claims by members of parliament.

The ancient institution of parliament has been damaged by a series of reports in the Daily Telegraph based on leaked information on how members milked the expenses system to supplement an annual salary of around 65,000 pounds ($100,700).

In a dramatic parliamentary session Monday, MPs publicly called for Martin to step down in one of the most extraordinary sessions of modern times. His authority was openly challenged and he faced a no-confidence motion signed by 23 MPs.

Conservative opposition leader David Cameron, well ahead of ruling Labor in opinion polls before a parliamentary election due by June 2010, said a very angry public was more concerned about having an early chance to vote than the choice of Speaker.

They want to elect a new parliament, he told BBC radio earlier. Their view is that swapping one person in a funny black costume for another funny black costume is not actually going to make all the difference, said Cameron, referring to the Speaker's ceremonial black silk robe.


Some analysts said the Speaker's departure would be only the first step in a purge of parliament, but believed Prime Minister Gordon Brown would fend off calls for an early election.

It is unlikely this will precipitate a general election, said Andrew Russell, a senior lecturer in politics at the University of Manchester.

I suspect the opposition will continue to call for an election and the government will continue to avoid having one.

Brown has called for fundamental reform of the expenses system to try to defuse a scandal that has damaged all the main political parties but is hitting his own Labor Party hardest after 12 years in power.

I have made it clear to the national executive of the Labor Party that no member of parliament, no candidate will stand for the Labor Party at the next election, if they have defied the rules, Brown told reporters Tuesday.

No minister will be in cabinet or in the government in future if it is proven that they have defied the rules.

Political leaders are keenly aware that the main parties are rapidly losing support, and fear voters may turn to fringe parties in local and European elections on June 4.

Brown has called a news conference for 5.30 p.m. (1630 GMT) Tuesday after a scheduled meeting with the Speaker and leaders of other political parties to discuss expenses.

(Additional reporting by Kate Kelland and Peter Griffiths)

(editing by Peter Millership)