Ewing’s husband Fergus and mother-in-law Winnie have accused Mary Scanlon, the Conservative candidate in Moray, of seeking to exploit her relationship with the politician, who died last month.

Scanlon recently issued a handwritten note to local voters, with the slogan: “Another bonnie fechter for Moray”. In the letter, she spoke of her friendship with Ewing and made no mention of the fact that she is a Tory.

“In me you can choose someone who has the same compassion and determination to do her best for local people,” she wrote. In another message, Scanlon told voters: “In many ways I have tried to model myself on her (Ewing).”

Scanlon’s attempts to cast herself as her natural successor have upset Ewing’s family, who were angry that Scanlon announced her candidacy so soon after her death.

In a statement issued by the SNP yesterday, Winnie Ewing, the former nationalist MSP, said: “Our main Tory opponents have been sending out tasteless letters, which hide their identity and pretend to be emulating Margaret. These Tories are nothing like Margaret. They are still anti- Scottish.”

Fergus Ewing, also a nationalist MSP, said: “It is folly to present oneself as being like another person. Nor would she (Ewing) ever have sought in her election material to hide the fact that she was a nationalist and SNP candidate . . . She would, therefore, I think, have been dismayed about some of the things that we have seen in this campaign — but not especially surprised.”

Last night Scanlon was unavailable for comment, but a Tory spokesman defended her tactics.

“They (Ewing and Scanlon) worked on many committees together and fought many causes together. Those are facts.

“We are not getting into a war of words with anyone or any negative campaigning. Mary is out campaigning on local issues with local people all across Moray. She’s proud to be a Tory and everyone knows she’s a Tory. We’ll concentrate on what we’re doing and saying and not on the words of anyone else.”

The SNP, defending a majority of 5,312, are favourites to hold the seat. But following their by-election victory in Dunfermline and West Fife, the Liberal Democrats are confident they can at least move from fourth to second.

Lib Dem sources say private polling has put the party in second place across the constituency — three points behind the SNP — and first in the fishing port of Buckie.

If the Lib Dems finish second it is likely to alarm Alex Salmond, the SNP leader, who is to challenge Nora Radcliffe, the Lib Dem MSP in neighbouring Gordon, at next year’s Holyrood election.

Campaigning in Moray yesterday, Charles Kennedy, the former Lib Dem leader, said a Lib Dem victory was “certainly on the cards”.

The Tories insist the contest is a two-horse race between them and the SNP. If they slide from second position in a constituency where they have traditionally enjoyed strong support it could raise questions about the leadership of Annabel Goldie.

Her performance since taking over from David McLetchie has already caused concern among some Tory MSPs.

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