By Shaun Ley
BBC presenter, Radio 4's The World This Weekend
In 1993, Canada's ruling party went from government to having just two MPs, after scoring just 16% in the general election. After Labour's electoral drubbing in June, could it face a similar fate?
Canada's first female PM warned Labour against changing leader
Kim Campbell, the first - and so far only - woman to become prime minister of Canada served for just four months in 1993, before leading the Progressive Conservative Party into a rout from which it never recovered.
Miss Campbell was chosen after Brian Mulroney, who had been prime minister since 1984, decided not to fight a general election which had to be held by the end of 1993.
She has some words of advice for those who tout David Miliband and Alan Johnson as potential Labour leadership challengers.
"I think the young whippersnappers who have the potential to lead the party successfully should bide their time," she told me.
"Don't take on a party when you don't have time to show who you are and why you're different. Because you're then just Gordon Brown, thinner and younger."
The Progressive Conservatives had seen their popularity nosedive - partly a result of a severe downturn in the economy similar to that seen in Britain today.
Before he left office, Mr Mulroney received the worst poll ratings of any previous Canadian prime minister, much as Gordon Brown has experienced in Britain.
The Progressive Conservatives, like Labour in the UK, had been the second party of government for most of the previous century.
They tended to be in office for shorter periods than the more dominant Liberals, and the government which had been in office since 1984 was their longest serving.
Before her election as leader, Kim Campbell was defence minister.
She had not been an MP for long, and was more of a "policy wonk" than a practitioner - a CV not too dissimilar from that of the Foreign Secretary David Miliband.
Despite her initial popularity, Miss Campbell says she did not have long enough before the general election to overcome the unpopularity of Mr Mulroney and the party.
She thinks a leadership change this close to a general election in Britain would be a mistake.
"A party can have a devastating defeat that then enables them to rebuild and to choose new leadership credibly, as opposed to a kind of desperate pass at the end of the game.
"You've already changed leaders once because you thought Tony Blair wasn't going to get you elected and Gordon Brown came in," she added.
"And now you're at the end of the game, maybe you could find a Kim Campbell but it's not really fair because you're really not giving him or her the chance to demonstrate change.
"And that's the problem - better for the unpopular leader to take the hit to enable a new leader to start afresh."
The Progressive Conservatives went into the election with 169 MPs.
They ended up with just two - and Kim Campbell was not one of them. The number rose to 20 at the next general election, but the party was on a downward spiral, and eventually it was wound-up.
Brian Mulroney - Canada's Gordon Brown?
Could Labour be facing an equally disastrous outcome here?
In the European Parliament elections in June, the party won 15.7% of the vote, a fraction lower than the Progressive Conservatives managed in Canada in 1993. It was Labour's worst performance in a nationwide election in 99 years.
The differences, however, are important.
The Progressive Conservatives were facing three major rivals, each of whom ate into their support.
Most Labour MPs think that would not happen in a general election, because the majority of voters tend to choose a party which they think can form a government.
Others, though, think Labour's poll ratings would not need to fall much further than they are now for the pressure on Gordon Brown to become overwhelming. One former cabinet minister told me this week that if they fall to 23%, then MPs will move against him.
Advice to Brown
However, the Canadian experience might make those agitating for Gordon Brown's departure think twice.
Rob Marris, Labour MP for Wolverhampton South West and a Canadian citizen, says such a move would amount to "window dressing", and would be treated by British voters in the same way Mulroney's replacement was in Canada.
Even Labour politicians who think defeat is all but inevitable can find some consolation in the Canadian experience.
Although the Progressive Conservatives were put firmly on the route to oblivion by the electorate, conservatism as an electoral force did not die.
The remnants of the old party and Reform eventually combined - which is why Canada has a Conservative government today, led by the former Reform Party activist, Stephen Harper.
Mind you, it took 13 years.
As for Kim Campbell, she has enjoyed a successful life after politics, first as a diplomat and an academic, now as a campaigner for good governance.
She thinks Labour should avoid creating its own version of her.
Instead, Gordon Brown should do what Brian Mulroney did not - face the electorate and take the consequences.
"If Gordon Brown believes in his policies and if he thinks he's done the right things, then losing an election will not be the end of his political credibility," she told me.
"It will give his party the chance to re-think things and choose a new leader who can go out with a fresh view. That's the right thing to do."