By Gavin Stamp
Political reporter, BBC News
MPs have many reasons for standing down, Chris Mullin believes
A former minister has dismissed suggestions of an "exodus" of Labour MPs at the next general election.
Chris Mullin said he did not "detect" signs that his parliamentary colleagues were resigned to losing and described such claims as "unhelpful".
Three times as many Labour MPs have opted not to contest the next election as Conservatives, with a year to go before a likely general election.
Mr Mullin predicted more would stand down but said this was not unusual.
The former minister, who himself is standing down as MP for Sunderland South at the next election, said the number of MPs intending to quit the Labour benches was not exceptional.
With Labour trailing the Conservatives in the polls and with continuing speculation about Gordon Brown's leadership, there has been talk of an exodus of Labour MPs in marginal seats.
Bob Marshall-Andrews, the MP for Medway who is standing down, said on Friday that it was "inevitable" Labour would lose.
Mr Mullin, who served as a junior minister between 1999 and 2005 and recently published a memoir of his time in government, said such remarks were "unhelpful", adding that he did not see any signs of an "end of era" mentality among his Labour colleagues.
"I don't detect anything like that," he said.
On Friday, Carlisle MP Eric Martlew become the 43rd Labour MP to say he would not contest the next election.
Mr Martlew, who is standing down after 22 years, said it was the right time to quit frontline politics while stressing that the Labour Party was "in good shape".
Of the Labour MPs who are not standing again, nearly a third have a majority of less than 5,000.
Mr Mullin said there may be some younger MPs who felt they could lose their seats but stressed there were a variety of reasons why MPs decided to stand down.
PROMINENT MPs STANDING DOWN
John Prescott (Lab)
John Reid (Lab)
Ruth Kelly (Lab)
Richard Caborn (Lab)
Gavin Strang (Lab)
Michael Howard (Con)
Clare Short (Ind)
Anne Widdecombe (Con)
"If you have been a minister and had a reasonably high-octane job and then you find yourself out of government then you might look around and think the caravan has moved on," he said.
For others, the realisation that they were "not going anywhere or doing anything useful" might lead them to stand down, he added, while others took the decision for personal reasons.
To date, 13 Conservatives - including former leader Michael Howard - have signalled they will be standing down.
Five Liberal Democrats and two others - former Labour minister and now independent MP Clare Short and former Conservative MP Derek Conway, expelled from the party over an expenses scandal - will also not be defending their seats.
Mr Mullin said the high proportion of Labour MPs leaving compared to Conservatives could be explained by the fact that they had many more MPs and had been in office for so long.
The numbers did not suggest an inevitable Tory victory, he said, despite statistics from recent elections pointing to a link between retiring MPs and the eventual outcome of the following election.
Before Margaret Thatcher's victory in 1979, 35 Labour MPs stood down, compared to 24 from the Conservative benches.
Ahead of the 1997 election, which swept Tony Blair to power, 72 Tories stood down, against 38 from the Labour side.
"There may be a small element of truth in it but the figures don't look that sparkling," he said.
The 1997 election saw the biggest post-war exodus of incumbent MPs with 117 choosing not to defend their seats.
In 2005, 84 stood down beforehand while 77 retired in 2001.
The publication of millions of potentially contentious expenses claims in July, under Freedom of Information laws, has prompted speculation that some MPs will be forced to stand down.