The SNP's internal feud reached new depths of bitterness last night when party leader Alex Salmond was told by treasurer Ian Blackford to apologise for criticisms made last week or face being sued for defamation.
As moves continued to oust Mr Blackford, the party was also preparing disciplinary action against one of his closest allies, Ms Margo MacDonald, who faces accusations of breaking internal rules by publicly challenging a parliamentary group decision.
Ms MacDonald, a critic of Mr Salmond's leadership style, will be dealt with on Thursday at a meeting which her supporters claim could mark the start of a campaign to have her deselected.
Nationalist spokesmen desperately sought to play down the effects of the furious row which erupted between Mr Salmond and Mr Blackford last week over reports that the SNP was in deep financial trouble.
Press officer Kevin Pringle refused to give details of the behind-the-scenes leadership attack on Mr Blackford at the weekend party executive meeting which passed a motion of no confidence in him by 18 votes to three.
SNP rules allow the executive to admonish, suspend or expel a member - which some observers think could be the leadership's next move if Mr Blackford stays put.
Party insiders have pointed privately to Mr Blackford as the source of recent stories about the SNP's financial state. Mr Blackford has hotly denied any wrongdoing. The cause of the row is Mr Blackford's reputedly hard line as treasurer in drawing up tough housekeeping rules for the party which is in debt.
He is thought privately to believe Mr Salmond and former chief executive Michael Russell, together spent irresponsibly during the Scottish Parliament elections and then left him to clear up the financial mess. Mr Blackford has repeatedly said that as a prominent and wealthy banker in Edinburgh he must ensure his conduct is above reproach because his professional reputation is on the line.
The latest dispute between the leader and treasurer involves the extent of the party's overdraft and the effectiveness of Mr Blackford's efforts to have it cleared before the General Election.
He and Mr Salmond were involved in an acrimonious dispute last summer after The Herald revealed that Stagecoach millionaire Brian Souter had made a major contribution - said to be about #200,000 - to the SNP but had not been named as the source. Rules at the time did not require the identity of major donors to be revealed but parties had agreed to abide by the spirit of the new procedures.
Mr Blackford irritated Mr Salmond, who claimed the SNP had behaved perfectly properly, with his insistence that there must be no ''jiggery pokery''.
Relations between the two men have never recovered and hit a new low last week with newspaper claims that the SNP was broke and had been forced to sell its Edinburgh HQ to help pay off an overdraft believed to be #400,000.
In fact, the SNP had planned long ago to sell its offices. The party is believed to have struck an agreement on the sale last week and it must now find a new headquarters.
Proceeds from the sale are not expected to be used in clearing the overdraft which deputy party leader John Swinney predicted last month would be paid off around the end of this year and which was about #600,000 at its worst.
Mr Blackford, who is reputedly wealthy, told Radio Clyde that when he was involved in talks with his bank about personally helping the SNP out of its financial difficulty, Mr Salmond was encouraging former party leader Willie Wolfe to run against him as treasurer. Mr Wolfe subsequently withdrew. ''I don't need lessons from Alex Salmond on integrity or trust,'' Mr Blackford said.
The SNP would not confirm a report that Mr Salmond accused Mr Blackford of incompetence and of destabilising the party and had appeared to blame him for the overspend.
He rejected suggestions that he and allies like Ms MacDonald were being purged as an offensive against dissidents. ''I don't believe in conspiracy theories,'' he said.
Mr Blackford pointed out that his treasurer's report to the national council last month had been accepted without questioning.
Ms MacDonald incurred the wrath of the leadership when she complained publicly about the parliamentary party's refusal to set aside SNP debating time in the chamber for her ideas for exploring the use of cannabis, particularly as an aid to those suffering pain. She accused some of her colleagues of ''reneging'' on the issue.
between the leader and treasurer.
Labour revelled in the SNP disarray. Scotland Office Minister Brian Wilson said: ''Alex Salmond's control freak tendencies have finally come home to roost. Having ousted the party treasurer in the night of the long sgian dubhs he has now turned his sights on the independence-minded Margo MacDonald.