Every Labour MP will be ordered to campaign in Glasgow East amid mounting panic that the party could lose the by-election in the constituency this month.

Party whips are launching an extraordinary operation to ensure that every minister and backbencher hits the streets on the tough estates of Easterhouse to try to stave off the threat from the Scottish National party (SNP).

The rearguard action is remarkable because Labour’s Margaret Curran will be defending a majority of 13,500. The SNP needs a swing of 22%.

The visits will be strictly monitored, with backbenchers required to clock in when they reach Glasgow. MPs have been warned the trips are not a “jolly” and that they must be seen to be doing the “donkey work” of canvassing.

Ministers who can show they have too much work on to make the 800-mile round trip from London will be required to contact voters by telephone.

The orders risk triggering a mutiny within the party, with many MPs struggling to hide their lack of enthusiasm for campaigning in one of the grimmest constituencies in Britain.

It could also prove extremely costly for Labour, which is already in financial trouble. The cheapest saver return tickets to Glasgow from London next week cost more than £100. MPs will not be able to claim the trip on parliamentary expenses and may turn to the party for help.

There is mounting speculation at Westminster that a defeat for Labour would prove terminal for Gordon Brown’s leadership. Party strategists admit that until this month, the seat had been seen as so secure that no campaign resources have been directed at it.

“It’s not as if we’re starting from any sort of base. We’re starting from absolutely nothing,” said one Labour official.

The latest YouGov poll put the SNP on 33% in Scotland, with Labour on 29%.

Alex Salmond, the SNP leader, has warned Glasgow East could be hit by a “political earthquake”. The constituency has the highest proportion of voters on incapacity benefit in the country with unemployment at 50% in some areas.

Religion could also play a part in the poll, which was called after the surprise resignation of David Marshall. The area is staunchly Roman Catholic and many voters are opposed to the embryology bill.

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