Alex Salmond yesterday sought to raise the stakes in the Glasgow East by-election by portraying Thursday's vote as a test of strength and personal popularity in Scotland between himself and Gordon Brown.

As the cliffhanger campaign in the constituency went into its final lap, the Scottish First Minister and SNP leader said that the by-election was “a tale of two governments” which had given voters in the constituency a chance to judge the relative performance of his administration in Edinburgh and Mr Brown's government at Westminster.

A typically buoyant Mr Salmond, speaking at a shopping district in the Easterhouse area as he campaigned for John Mason, the party's candidate, also issued a last-minute challenge to Mr Brown to a head-to-head debate in Glasgow East. He claimed that Scots were “pretty satisfied” with the performance of the SNP government at Holyrood and added: “This by-election is a test of strength between two governments.

“If the Prime Minister can get to Glasgow East, I would be very happy to have an individual debate with the Prime Minister. I would love to do that, but I do not expect to see him.

“Any by-election is a test of every party that contests it. One aspect of this by-election is that this is a tale of two governments. People are passing judgment clearly on the Labour Government at Westminster and the SNP government in Scotland.”

Mr Salmond's tactic is to try to personalise the Glasgow East battle in order to capitalise on opinion poll ratings that show about 50 per cent of Scots think he is doing a good job as First Minister, while Mr Brown's approval ratings across the UK have been the worst of any prime minister in recent times.

Labour immediately accused Mr Salmond of “vanity”, with David Cairns, the Scotland Office Minister, saying: “This by-election is not about the ego of Alex Salmond. It is about the people of the East End of Glasgow. Mr Salmond has already declined a chance to debate with me on television and he should concentrate on telling the truth about his administration's broken promises.”

At his campaign stop yesterday, Mr Salmond avoided giving a direct answer to questions on whether he thought that voters who did not support Scottish independence might still vote SNP. “I want every vote. I have long abandoned the idea of analysing a vote. Politicians should be grateful for every single vote they can get.”

In the final two days of the campaign, both Labour and the SNP are concentrating on reaching undecided voters and both parties still say that the contest is neck and neck. The bookmakers, meanwhile, continue to make Labour slight favourites at odds-on 1-3, while the SNP are 9-4 against.

Labour believe that it can turn some negative media coverage of the constituency, courtesy of newspaper articles and broadcasts concentrating on deprivation, to their advantage.

Margaret Curran, the Labour candidate, attempting to plug in to local exasperation at the tone of some of the coverage, yesterday said that she would “never, ever talk the East End down”. She added: “The people in this community are sick and tired of being talked down - from the Nationalists comparing the area to the Gaza Strip to sneering Tory commentators deliberately ignoring the improvements of recent years.”

Mrs Curran claimed that there had been “a bit of a shift” in recent days towards Labour among previously undecided voters, and she added: “There has been the need for someone to articulate the strengths of the East End of Glasgow and stand up for it when it is required.”

Meanwhile, Labour declined to comment on report in the Scottish edition of The Sun that said that the daughter of David Marshall, the retiring MP for Glasgow East, operated two private companies from the Marshall family home, which also houses Mr Marshall's publicly funded office.

The report said that Christina Marshall registered the property companies based at her father's home in March. Mr Cairns said: “As far as we are concerned, David Marshall stood down as an MP on doctor's orders. Two doctors' letters said he wasn't fit to carry on, and we have accepted that.”

Mr Salmond refused to be drawn into the controversy, saying: “I saw the story and it is for the Labour Party to answer.”

However, Ian Robertson, the Liberal Democrat candidate, said: “Some serious questions have to be asked of Mr Marshall and the Labour Party. I for one will be looking for assurances that no taxpayers' money was used for personal gain.”

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