Raymond Buchanan looks at the career of Michael Martin
Labour is preparing for a tough by-election in Glasgow following the resignation of Michael Martin as Commons Speaker.
Mr Martin, who has been criticised over the MPs' expenses scandal, will step down from the role on 21 June.
He is also expected to quit as the MP for Glasgow North East, a traditionally safe seat for Labour.
The contest could take place in September, the local party chairman said.
Mr Martin was criticised for leading efforts to block the publication of MPs' expenses, since revealed by the Daily Telegraph, and was facing a motion of no confidence in him backed by more than 20 MPs.
The Glasgow North East by-election will come after the SNP won the Glasgow East Westminster by-election in July 2008 - overturning a Labour majority of 13,507 to win with a swing of 22.54%, by just 365 votes.
I understand people from Springburn, in his constituency, have been contacting him and his office urging him to stay on
Lord Foulkes Labour peer
In the more recent Glenrothes by-election, Labour saw off a strong SNP challenge to hold the Fife seat.
The chairman of Mr Martin's local Labour Party, Gerry Leonard, told BBC News the SNP would put up a "tough fight" in Glasgow North East, adding: "It's a challenge for us, but I really believe we will succeed in that."
Mr Leonard added: "Michael's not decided when he's resigning as an MP, but I would think that would probably happen in June and then, we will move forward to a by-election, maybe in September."
Mr Martin, who has been an MP for 30 years and Speaker for nine, is widely expected to move straight into the House of Lords when he steps down.
But Labour peer Lord Foulkes said it was possible for Mr Martin to continue as an MP.
"I understand people from Springburn, in his constituency, have been contacting him and his office urging him to stay on," said Lord Foulkes, a former MP currently serving as an MSP.
Meanwhile, Scotland's First Minister Alex Salmond called for an early general election in the wake of Mr Martin's announcement.
Mr Salmond described the Speaker as 'a decent man who made a mistake'
He said Westminster should adopt interim expenses rules based on the Scottish Parliament system of "total transparency" while an audit of MPs' claims over the last four years is carried out.
The SNP leader described Mr Martin as "a thoroughly decent man who made a mistake", adding that he had been "a bit of a fall guy for the system".
Mr Salmond, who sits both as an MP and an MSP, said: "There should be a general election because it's not a question of people just having no confidence in the speaker - it's a question of people having no confidence in the Westminster system.
"If anybody among the MPs believes they can just get rid of the speaker and everything else will be hunky-dory, I think they have another thing coming."
The first minister added: "I'd have thought that once that audit is done of MPs' expenses over the last four years, then the case is overwhelming to have an early general election."
"There can be no argument against the entire House of Commons submitting itself to a vote of confidence, or otherwise, of the people who elected them," he said.
The departure of Mr Martin - marking the first time in 300 years a Speaker has in effect been forced out - will allow his successor to be elected on 22 June.
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