The SNP may need to be replaced by a new "untainted" pro-independence party following a "volcano" of revelations in a forthcoming book by Alex Salmond, the party's former deputy leader has said.

Jim Sillars compared the aftermath of Mr Salmond's trial, in which he was cleared of a series of sex assaults, to an "eruption" that will shake the Nationalists.

He said there has been a "rot" at the heart of the Nationalists for years, but there may need to be "a complete clear-out of the highest levels" before it is fit to lead the country again.

Mr Salmond is using the coronavirus lockdown to write a book that will target the senior party figures he believes were behind a political conspiracy to ruin him.

The SNP has denied such a conspiracy. It will cover the period from when he was first accused of sexual misconduct in January 2018 through to his recent acquittal on 13 charges at the High Court in Edinburgh.

Mr Sillars, who was Mr Salmond's mentor, said that “the trial of the SNP both at party and parliamentary level” would begin when the threat from the virus has lessened.

Although many senior SNP figures are divided between camps supporting Mr Salmond and Nicola Sturgeon, he said he was in neither group.