Lib Dems eye Michelle Thomson seat if she quits

Mike Crockart and Michelle Thomson pictured at the Edinburgh count for the UK general election 2015. Picture: Lisa Ferguson

Ms Thomson defeated Mr Crockart in Edinburgh West at the general election by a majority of 3210.

But if she decides to resign from the Commons – sparking a by-election – Mr Crockart is expected to bid to win the seat back.

Ms Thomson, who came to prominence during the independence referendum as a leading figure in Business for Scotland, has been mired in controversy for more than a fortnight after claims she has built up a buy-to-let property portfolio by buying homes at knockdown prices from families struggling to pay their mortgages.

Police have launched an investigation into transactions handled by Ms Thomson’s former lawyer, Christopher Hales, who was struck off for his involvement in property deals linked to the MP.

Ms Thomson has consistently denied any wrongdoing and has withdrawn herself from the SNP group at Westminster, stepping down as business spokeswoman, while she focuses on clearing her name.

Reports at the weekend claimed the SNP had already started preparing for a by-election, with an emergency meeting held in the constituency last week.

And one SNP insider was quoted saying: “It is going to be a very hard seat to hold.”

A Lib Dem insider said Mr Crockart was almost certain to be chosen as the party’s candidate if there were to be a by-election.

“Mike is still very well regarded and still very active,” said the source. “He would have to get selected, but he’s the obvious person to stand and he would have the best chance.

“He has not taken another job yet – he has had a few offers, but he’s taking a bit of a break to decide what he wants to do.

“It would have to be a decision for him and his family. The last time was pretty bruising, but I think he would go for it.”

Mr Crockart took 33 per cent of the votes at the election in May, while Ms Thomson got 39 per cent and the Conservatives and Labour both around 12 per cent. Mr Crockart, a former policeman, worked with Ms Thomson at Standard Life about 15 years ago, when she was his line manager.

Quizzed at First Minister’s Questions last week, Nicola Sturgeon insisted she had not been aware of the allegations against Ms Thomson until they were published in a Sunday newspaper.

But she said: “I am in no doubt whatsoever in my mind that if the allegations – and again I stress the word allegations – are proven to be correct, they will represent behaviour that I find completely unacceptable.”