Alex Salmond claims Danny Alexander has been "caught red-handed" with "scaremongering" claims about the impact of Scottish independence.
The SNP leader told the BBC the Treasury's calculations had been "blown to smithereens" by the same academic whose work underpins the British Government's analysis.
Professor Patrick Dunleavy of the London School of Economics said Treasury figures about the cost of setting up a new independent government were "bizarrely inaccurate".
Mr Salmond seized on Professor Dunleavy's words, saying: "We have the Chief Secretary to the Treasury left with no credibility whatsoever. He’s been caught red-handed engaged in a scaremongering campaign.”
More top news
Flights from UK airports were an average of 15 minutes late in 2017.
The Royal Horticultural Society has already pledged its Feel Good Garden will live on at a Camden and Islington Mental Health Trust site in
The Foreign Affairs Committee says it is ‘business as usual’ in the City for Kremlin allies despite the Salisbury nerve agent attack.