SCOTTISH Labour’s left wing has launched an astonishing attack on Kezia Dugdale and the party leadership, accusing them of ruining Jeremy Corbyn’s chances at last month’s general election with their “Better Together mindset”.

The Campaign for Socialism, whose convenor is MSP Neil Findlay, and whose members include new MPs Hugh Gaffney and Danielle Rowley, the daughter of party deputy leader Alex, said Scottish Labour’s “send Nicola a message” campaign about independence “tacitly oversaw the Scottish Tories increase their votes by approximately 5,500 in the average constituency”.

Using analysis carried out by CfS vice chair Lesley Brennan, the report says Dugdale and the Scottish party’s campaign killed the “Corbyn bounce” seen across the rest of the country.

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Ironically, the report, which is bound to open up divisions in the party north of the Border, says Labour could have been done better if they had been more united.

“Labour’s disunity – especially with senior figures in Scottish Labour’s leadership team being openly hostile towards Jeremy Corbyn – turned people off,” the analysis states.

The report goes on to say the “framing of the election around the SNP and the constitution, avoided robustly challenging the Tories on their record in Government in Westminster”

The report says UK Labour increased its number of votes in 607 out of 632 seats. Of the 24 seats where there was no increase, 21 were in Scotland.

A Campaign for Socialism spokesperson said: “While it’s great we won some seats back, it’s clear that the campaign here failed to deliver. While elsewhere we seen people being enthused by ‘for the many, not the few’ we concentrated on the dispiriting visionless ‘send Nicola a message’ – and paid a price for that, coming third in votes and seats for the first time in a century.

“In Scotland we looked more like Jim Murphy’s Labour Party than Jeremy Corbyn’s – and that isn’t a good look.”

Labour have managed to keep a lid on the infighting in the wake of the strong General Election result, with MPs and Corbyn the most united they’ve been in years.

But the accusation that Dugdale and Scottish Labour held the party back could lead to reopening of bitter divisions, and could even pave the way for a leadership challenge.

The report ends with a call to keep “the momentum of Jeremy’s campaign going and planning ways to sustain this for the forthcoming 18 months; especially, given the SNP’s concern that after another snap General Election they could be down to three MPs.”

The SNP’s James Dornan called the report “devastating” for Labour.

He added: “Kezia Dugdale should hang her head in shame at that verdict from her own colleagues.

“This report also lays bare the splits inside Labour and outlines what everyone in Scotland already knows – that Labour north of the Border spends all its time attacking the SNP while letting the Tories off the hook.

“That is the damning verdict from Labour members themselves, and it is a huge embarrassment for Kezia Dugdale and others at the top of the party, who remain locked in Better Together mode.

“It is no surprise that with Ms Dugdale having spent so long undermining Jeremy Corbyn, his allies are now sharpening their knives for her.”

In response to the report, a Scottish Labour spokesman said: “The overwhelming majority of Scottish Labour members are united behind our vision for a Scotland that is part of a United Kingdom which works for the many, not the few.

“Scottish Labour ran a positive pro-UK anti-austerity campaign that highlighted how we would improve the lives of people across Scotland. That dual message directly led to six gains for the Labour Party.”

A senior Scottish Labour source speaking to the Politics Home site, pointed out that Brennan, had come third behind the Tories in Dundee East.

The source added: “The Campaign for Socialism clearly didn’t get Jeremy’s memo about the need for unity as we try to oust the Tories.”

The report comes as Corbyn announced a tour of marginal constituencies in Scotland for next month, in his bid to keep the party on an election footing in case Theresa May’s minority government collapses.

Of the 64 seats Labour needs to win to secure a parliamentary majority, 18 - more than a quarter - are in Scotland.

Corbyn is to visit Glasgow South West, Glasgow East, Airdrie and Shotts among others.