Nicola Sturgeon has been branded "out of her depth" as SNP leader and lacking "political nous" by former party Deputy leader Jim Sillars.
The former Govan MP accused Ms Sturgeon of a "fundamental political misjudgement" in pushing for a quickfire second independence referendum after the Brexit vote, blaming this for the party's heavy losses in this year's UK election.
He was writing in the Daily Record today and called for the independence movement in Scotland to extricate itself from the SNP - as it is too tied to the party's electoral fortunes.
Mr Sillars has always been an ardent critic of the EU, which said an independent Scotland would face a lengthy wait to join during the referendum three years ago. The Nationalist veteran has hit out at a motion in this weekend's SNP conference which praises Brussels.
"As long as the EU are there, denying Scots membership, we have fatal uncertainty injected into our debate," he said in today's article.
"The independence movement must reconsider their relationship with the SNP, especially in light of the error-strewn course taken by leaders with no strategic nous, out of their depth.
"They lunged into an exercise in monumental political misjudgement – the demand for a premature second referendum, leading to loss of majority at Holyrood and a near wipeout in the North East, Borders and Galloway in the Westminster election."
But a spokesman for the SNP pointed to Mr Sillars’ support for the left-wing RISE Coalition at the Holyrood election last year which was committed to a second independence referendum by 2021.
“Jim Sillars is contradicting himself – he backed an independence referendum at the last Holyrood election, before Brexit had even happened,” the spokesman said.
“And he now finds himself against the majority of Scottish opinion, which is firmly opposed to the Tories’ extreme Brexit plans and the damage they will cause.”