The SNP leader Nicola Sturgeon has attacked claims in a newspaper report that she would prefer the Tories to be in power instead of Labour, describing them as "dirty tricks" and has called for an inquiry into the leak.
The Daily Telegraph's report claims that Sturgeon made the statement during a private meeting with Sylvie Bermann, France's ambassador to the UK.
The newspaper published a transcript of what it claims is an official British government memorandum on its website, detailing the content of their conversation.
Sturgeon said that she would ask civil service head Sir Jeremy Heywood to look into the leak.
In an interview on the BBC News Sturgeon forcefully denied the report, saying: "The real issue is how a second-hand and inaccurate account of this meeting – which was not even attended by the UK government – came to be written by a UK government civil servant and then leaked to Tory-supporting newspapers at the start of a general election campaign.
"It suggests a Whitehall system out of control – a place where political dirty tricks are manufactured and leaked. And the Foreign Office now appears to be denying the very existence of such a document."
During Scotland's independence referendum, senior civil servants in Edinburgh and London were accused of bias, with the former supporting the "Yes" vote and the latter supporting the "No" camp.
Sturgeon had earlier "categorically" denied the claims made by the Daily Telegraph on Twitter.
.@simon_telegraph your story is categorically, 100%, untrue...which I'd have told you if you'd asked me at any point today
— Nicola Sturgeon (@NicolaSturgeon) April 3, 2015
She also retweeted what appeared to be a statement from the French Embassy press office and the British Foreign office.
Foreign Office spokeswoman tells me they have no record of memo behind @NicolaSturgeon story. "We are not aware of such a document."
— Nick Eardley (@nickeardley) April 4, 2015
Sturgeon's popularity is flourishing after her convincing performance during this week's televised leaders' debate.
The leader of the SNP has hinted at offering informal support to Ed Miliband, should he become prime minister, in return for abandoning already implemented Tory austerity policies.
But she has ruled out a deal of any sort with the Conservatives.
The alleged comments were earlier picked up by Labour leader Ed Miliband who described them as "damning".
Miliband told Sky News on Saturday: "I think these are damning revelations. What it shows is that while in public the SNP are saying they don't want to see a Conservative government; in private they are actually saying they do want a Conservative government. It shows that the answer at this general election is if you want the Conservatives out, the only answer is to vote Labour for a Labour government."
The SNP is on course to take up to 50 seats from Labour in Scotland, according to some polls.