Scotland's embattled first minister still has the support of the prime minister despite the continuing row over his constituency office expenses.

Downing Street said on Monday that the prime minister was "fully aware" of the current situation surrounding Henry McLeish and he would continue to be supported by Tony Blair.

"Henry McLeish has the full confidence of the prime minister," the Number 10 spokesman said, adding the row was entirely a matter for McLeish.

Labour's leader in the Scottish parliament has faced mounting criticism after it was revealed he had sub-let half his constituency office while at the same time claiming the whole bill from the taxpayer. McLeish admitted it was "an error" and paid back £9,000 to the Commons' authorities.

Both the Inland Revenue and Fife police are now investigating the matter and McLeish will face questioning from his own MSPs on Tuesday and a full parliamentary debate on Thursday.

The whole issue has brought back into the public eye the less savoury side of Labour's Scottish politics and memories of the Monklands affair in what was the then Labour leader John Smith's constituency. Senior party officials say although the episode is embarrassing for McLeish personally, the old Labour days of a "tartan mafia" dominating local politics are over.

"People are scratching around to find something that isn't there. At national level people have wised up. If we are going to have a debate about probity then let's do it with all the parties and start at local level," said one senior Scottish backbencher.