Labour's only Scottish MP has accused Jeremy Corbyn of a lack of understanding of the political dynamic in Scotland by failing to rule out an alliance with the SNP.
Ian Murray, who resigned as shadow Scottish secretary in June, said the SNP's proposal for full fiscal autonomy would create a £7.6 billion hole in Scotland's economy.
His successor Dave Anderson, the English MP appointed to shadow the Scotland and Northern Ireland portfolios, said an SNP alliance may be a price worth paying to stop another Conservative government.
Writing in the Daily Record, Mr Murray said: "Jeremy Corbyn isn't interested in being Prime Minister. Owen Smith, the other candidate, understands the need for a Labour Government.
"He knows that to help working class families get a fair crack of the whip, we need to appeal to as many people as possible.
"Supporters of Jeremy Corbyn appear to be doing the exact opposite.
"In recent days my successor as shadow scottish secretary, Dave Anderson MP, suggested there could be a deal between Labour and the SNP to form a UK Government.
"This isn't the first time Jeremy and his allies have shown a lack of understanding of the political dynamic in Scotland.
"During the passage of the Scotland Act, the SNP were forced by right wing Brexiteer Tories to table an amendment that would have blown a £7.6 billion hole in Scotland's finances.
"People across the UK need a Labour Government.
"Only an Owen Smith win will restore credibility to our battered party and give hope that the Tories can be thrown out of office."
Asked about an SNP coalition on Thursday, Mr Anderson said: "It is far too early to even contemplate that, but what I am not prepared to do on behalf of the Labour Party nationally is to rule that out completely.
"If that is the price we have to pay to prevent another rabid rightwing Tory government then, I tell you what it is, we have got to at least think about it and discuss it."