Alistair Darling, who leads the Better Together campaign, has insisted Mr Salmond is engaging in the politics of deflection, using the issue of the TV head-to-head with the PM to distract people away from holes in SNP policy. The former Chancellor, who insisted he spoke for Scotland on the independence issue, challenged the First Minister to debate with him and not Mr Cameron.
But Mr Salmond has maintained that Blair Jenkins, who leads the Yes Scotland campaign, is the more appropriate opponent for Mr Darling.
One senior Whitehall insider said: "The Scottish Government might continue to bang away at this, but it's a non-starter. There is absolutely no way the Prime Minister will debate with Salmond. This is not about Salmond versus Cameron. This is about Salmond versus Scotland."
In a new letter to the Prime Minister, Mr Salmond insisted: "It is not possible, with any degree of consistency or credibility, to involve yourself and your government so centrally in the referendum process and then refuse to publicly debate these very issues."
While No 10 again insisted the campaign should be led by Scottish voices, the Better Together campaign branded Mr Salmond's renewed attempt to get Mr Cameron in front of the cameras for a face-to-face debate on St Andrews Day as "more divisive nonsense from the separatists".