Douglas Alexander visited Glasgow this weekend in an attempt to drum-up support for Labour in a clear sign that the government are concerned about a critical by-election in the city this month.

Mr Alexander – brother of Wendy, who just last month stepped down as Labour’s leader in Scotland – is among 39 Scottish MPs who have been urged by the prime minister to travel north to help the campaign.

The moves come amid fears that the Scottish National party will claim Glasgow East in the July 24th by-election – prompted when David Marshall, who had a majority of about 13,500, was forced to step down due to health reasons.

However, the prospect of defeat at the hands of the SNP appeared to strengthen on Sunday night after a weekend of chaos surrounding the selection of a Labour standard bearer.

Favourite candidate George Ryan, a local councillor, withdrew citing the “pressures” on his family if he became an MP.

Labour will be hoping to restore some momentum by selecting Margaret Curran, at present a member of the Scottish Parliament for Glasgow, as its candidate.

Ms Curran said that she hoped for a “spirited” campaign. “I am putting my name forward because I’m deeply committed to the communities of the east end of Glasgow,” she said.

Internal polling by Labour shows that the party’s majority in the seat has fallen to as little as 5,500, according to a Scotland on Sunday report. Labour is concerned about a catastrophic defeat in the city – once an impregnable party stronghold – since the loss of Crewe and Nantwich, and the waning poll ratings.

No candidate for Glasgow East and any leader in Scotland Alex Salmond, first minister and SNP leader suggested that Labour was in “complete meltdown”.