GLASGOW EAST BY-ELECTION SPECIAL REPORT: Labour admit it�ll be a sweat to hold on to one of their safest seats; the SNP insist there�s a mood of change that will go their way. Our report looks at the battle for Glasgow East as it enters the home stretch

On the pristine lawn of a smart bowling club that could well have been in the middle of Hampstead rather than Glasgow East, Alex Salmond yesterday launched the SNP into their final stretch of campaigning. Before rolling a specially chosen yellow bowl towards the jack, the first minister asked one of the Garrowhill club members: "Which side am I coming in from?" Late this Thursday night, when the ballot boxes from the by-election have been counted, Salmond believes the answer will be "the winning side".

The Nationalists' optimism isn't shared by Labour and their candidate, Margaret Curran. The Holyrood MSP left the spin and the bowling to Salmond and her main opponent, John Mason, insisting that even though a new Progressive Scottish Opinion poll for the Daily Mail had put Labour 17 points ahead of the SNP, she would still be campaigning over the final four days as though Glasgow East was a Labour marginal, and not her party's 26th safest seat.

Outside Asda at the Parkhead Forge shopping centre, Curran, as she has throughout the campaign, performs as though she has met everyone in Glasgow at one time or another. Labour's message, which has been refined as the brief campaign has progressed, is that Curran would go to Westminster insisting much more needs to be done for this constituency. So is she contemplating becoming a serial rebel and a member of the "awkward squad"? She says no. "Voting against the government on a regular basis isn't the way forward," she says. Forget new Labour or complacent Labour. Curran, if she wants to win, believes she has to be the aggressively independent Labour candidate.

The Daily Mail poll contradicts the private canvass returns that have been telling both Labour and the SNP that Thursday night will be close; very close. At the 2005 general election, David Marshall took the seat with just over 60% of the total vote. The SNP came second, way back on 17%.

With a large protest vote against the government losing them the Crewe and Nantwich by-election to the Conservatives in May, and month-on-month opinion polls putting Labour up to 20 points behind the Conservatives, for Curran to drop just 8% of the 2005 vote would be a triumph beyond all Downing Street's expectations.

However, Labour's own polling, according to senior party sources, has left them believing a win is likely, but losing is still possible. "It will be a sweat," said one party worker.

If there is any sweating in the SNP ranks, it doesn't show. Neither Salmond's nor John Mason's bowling will take them to the 2014 Commonwealth Games team, but in Garrowhill Salmond was confident other things were going his way. "There is a mood of change in this constituency, change for the better and I believe it will take us over the line this Thursday because of the work that's been put in by a motivated and strong support."

Although Salmond said the SNP were only marginally short of reaching a winning target of 45% of the vote, his party's private canvass returns paint a tougher picture. This shows them with 22%, four points behind Labour on 26%. That's a huge swing to the SNP, but with their figures also showing 35% have still not decided how they will vote on Thursday, neither party has any reason to be complacent about who will win.

The soft-spoken Mason said his strategy for the remaining days of the campaign would be to reassure wavering Labour supporters that a vote for the Nationalists would be "safe" because it would not change the government.

"I'm under no illusion about how difficult it is for people who've normally voted Labour giving us their vote. But this is a by-election, not a general election."

He added: "We've seen the muddle the government are in this weekend discussing the abolition of incapacity benefit. We can send a message from the east end of Glasgow that this isn't going to help those who really can't work."

Those around Curran, who accept there have been a few gaffes, were taking some pleasure in seeing the first major error from the SNP. Leaflets from the Nationalists were all recalled and an apology issued after they showed the faces of police officers alongside Scotland's justice minister, Kenny MacAskill.

The Police Federation was furious, saying it looked like the officers were endorsing Mason.

"They should be ashamed of themselves," said the Scotland Office minister at the head of team Curran, David Cairns. The SNP apology and recall of all the leaflets was "humiliating", he added.

Outside Asda, no-one brought up the humiliation. So was it an issue? Dave, pushing his trolley, said: "No, not an issue at all." Why? "Because I'm off on holiday tomorrow and my postal vote was too late. So me, the missus and all the grandparents - no votes from us. And there's plenty of us. That's an issue."