However, doubts have been raised about whether Mr Leonard will attend the Labour group’s annual “away day”, with party sources suggesting he may be “considering his position” as leader after he was undermined over a second independence vote by John McDonnell.

The Shadow Chancellor last week said a Labour UK government would not block a second referendum if the Scottish Government asked for one, and despite talking to Mr Leonard he then doubled-down on his statement and revealed that Jeremy Corbyn supported his view.

The internal row that erupted was inflamed by the resignation of the long-serving general secretary, Brian Roy, and the revelation yesterday that the party had seen its income fall by more than 60 per cent in the last year.

The Scottish Labour parliamentary party is set to meet in Glasgow to focus “on our campaigning to remain in and reform both the EU and UK; the forthcoming legislative programme and the development of our progressive policies”.

But Labour insiders say the day, which was arranged before last week’s meltdown, will now be a crisis summit on the future of Mr Leonard’s leadership.

A party source said: “People were furious last week with how John McDonnell arrived in Edinburgh and changed policy and just cut the legs out from under Richard. It was an appalling way to treat him and party members as a whole and I think many people were actually more concerned about that than even what it was that McDonnell said.

“The meeting won’t be angry, but more full of despair and a pleading with Richard to show some leadership, stand up to the UK party and not let them write off Scotland and the party here in their total focus on doing anything to get Corbyn into Downing Street.

“But we will also have to discuss how we go forward with the recruitment of a new general secretary and how we start attracting more funds because the financial situation is precarious.”

Another insider said: “If Richard thought being an ally of Corbyn and McDonnell would mean they supported his leadership, then he’s been brutally shown that is not the case. They are not interested in him or what he wants to achieve in Scotland, they’re interested only in themselves.

“Richard had to be convinced to stand for the leadership and now the same people who told him he could do it are undermining him and giving him terrible advice.

“If he’s not considering his position I’d be staggered.

“If he turns up to the meeting, then he’ll find that what the group wants is for him to say something, do something to show he’s his own man and that this is a point of principle. Otherwise how will he possibly be able to face going back into Parliament when it returns from recess? It is utterly depressing.”

The row began last Monday with Mr McDonnell’s appearance at a Fringe event where he said Labour would not block a referendum for democratic reasons.

A meeting with Mr Leonard, in which the Scottish party’s opposition to a second vote was stressed to Mr McDonnell, did nothing to ease the row, with the Shadow Chancellor repeating his stance at another Fringe event.

By Friday Mr Roy had resigned as general secretary, with sources claiming he had been forced out, and yesterday it was revealed the last year had seen the party raise the lowest amount in income in 20 years.

A spokesperson for Scottish Labour said: “Richard Leonard has made clear his view that Scotland needs radical, reforming Labour governments at Holyrood and Westminster – not more constitutional division.

“We need transformative Labour policies that will invest £70 billion in the Scottish economy and create prosperity. That is what Scottish Labour is focused on as we head towards the possibility of a snap general election.”

Scottish Labour in crisis summit as party implodes