Just when it seems the Scottish Labour Party can inflict no more damage upon itself, it finds a fresh appetite for pointless masochism.

After almost a decade of decline, during which the party has fallen from a position of complete political dominance into third place behind the all-conquering SNP and the rejuvenated Scottish Tories, Labour can’t seem to get back on its feet never mind mount a serious electoral challenge.

Kezia Dugdale - Scottish Labour’s sixth leader in nine years - has tried to bring a degree of calm to a party that’s been in a perpetual state of self-destruction since the nationalists first came to power at Holyrood in 2007. But even the affable, level-headed Dugdale has no answer to the Jeremy Corbyn effect which has spread north and is now tearing what’s left of Scottish Labour apart.

After Dugdale last week added her voice to the chorus of those calling for Jeremy Corbyn to step down as leader of the Labour Party, her own deputy led calls for him to stay.

Alex Rowley MSP - a former General Secretary of Scottish Labour - and two Scottish Parliamentary colleagues, Neil Findlay and Richard Leonard, issued a statement demanding loyalty to Corbyn. The trio insisted that the Leader of the Opposition had won the support of party members because he offered “an alternative to the austerity driven divisions within our economy and society”.

Dugdale, unsurprisingly, was livid. And she was to become angrier, still.

Last Friday, Rowley took the step of writing to every member of the Scottish Labour Party, outlining in detail why he believed it was essential for them to unite behind Corbyn. As if this act wasn’t quite enough of a slap in the face to Dugdale, her deputy quoted the words of SNP First Minister Nicola Sturgeon to support his case.

Sturgeon had been right when she told the Scottish Parliament that it was the Conservative Party that had “recklessly brought this country to the brink of disaster”.

Friends of Dugdale have since pointed out that Rowley, when seeking election as the Scottish Party’s deputy leader last year, promised that if he won he would not accept a protected place at the top of one of the lists from which a 56 of Holyrood’s 129 MSPs are elected under a system of proportional representation only to go back on his word as soon as he won that particular race.

“How,” asked one MSP loyal to Dugdale, “can Rowley have the brass balls to lecture anyone about loyalty and doing the right thing? He’s only loyal to Alex f****** Rowley.”

Dugdale’s view that Scottish Labour will not start to rebuild support in Scotland would seem to be correct. The SNP might talk a radical game but it is positioned slap bang in the political centre ground, with policies that wouldn’t have looked out of place in Tony Blair’s New Labour.

But there are those in Labour north of the border who have convinced themselves that the answer to a huge successful centrist political project is a lurch further to the left.

All of this adds up to a thwocking great migraine for Dugdale who was already struggling to make her party seem relevant. The nationalists have successfully positioned themselves as the choice of those Scots who identify as progressives, while the Tories have won the support of those for whom the preservation of the UK is a defining concern.

Jeremy Corbyn’s continued presence at the top of the UK Labour Party threatens it with electoral annihilation. Scottish Labour, already badly wounded, might be finished off for good by the collateral damage caused by his fight for political survival.