THE Scottish National party is on the brink of claiming a historic victory in the Glasgow East by-election as Labour’s campaign this weekend descended into chaos.

Private polling by the nationalists reveals it is on 22% of the vote, four points behind Labour. But, with just four days until polling, 35% of voters are still undecided.

Labour’s efforts to canvass support have been hampered by crippling computer problems. Software imported from England was unable to recognise twin-number Scottish tenement addresses, leaving campaign organisers to record voting intentions manually.

The computer program recorded tenements on the wrong streets or missed them out altogether. Other problems included the occupants of whole blocks recorded as living in one flat.

In addition, hundreds of man hours have been wasted on pointless journeys as volunteers were sent canvassing with out-of-date maps.

Meanwhile, Margaret Curran, the gaffe-prone Labour candidate, is facing fresh accusations of arrogance and complacency after she admitted that she had not even read a personal letter, signed by herself and sent to every voter in the constituency.

Yesterday Alex Salmond, the first minister, made his eighth visit to the constituency to target swing voters. His party is seeking to exploit Labour plans to force incapacity benefit claimants to work for state support instead. With 11,000 of the Glasgow East electorate on the benefit, it is sure to prove an unpopular measure.

Predicting victory on Thursday, he said: “Our support is strong, motivated and it’s going to turn out. The only reason people are undecided is because they are moving from the Labour party to the SNP.”

A Sunday Times reporter spent a fortnight working undercover on the Labour campaign and found disorganisation and panic, with campaigners terrified of being defeated by John Mason, the SNP candidate.

Curran began the campaign claiming that she had lived all her life in the east end, but was later forced to admit that she lives in a £600,000 southside villa. She is under renewed fire over a campaign leaflet.

The letter, which features her photograph under the slogan “Standing up for the East End”, states: “I am Glasgow born and bred. I have fought for our community all my life and now I am in a fight to stand up for you at Westminster.” However, she later admitted that she was ignorant of the contents of the letter.

Last night opposition politicians claimed that Curran’s attitude is typical of her party’s disarray. “The Labour campaign is clearly in chaos. In the past few days their materials have become increasingly shrill and negative and now we know why —

panic,” said Angus Robertson, campaign co-ordinator for the SNP.

“The fact that the party imported an inappropriate IT system from England is symptomatic of the political and organisational mess they are in.”

David Cairns, Labour’s campaign spokesman, defended Curran, saying: “What goes out in the name of the candidate are sentiments that the candidate is entirely comfortable with.

“This has been an extremely effective and very well-run campaign. Does that mean to say that absolutely everything — especially when you’re dealing with computers — has gone completely perfectly? No. But no campaign can tell you that.”

Times Recommends

• DIY video helps the WI get to grips with sex
• Artists urge nation to save Titians
• Go home, Iraqi leader tells Britain