THE leader of the UK’s largest trade union has launched an extraordinary attack on Scottish Labour leader Kezia Dugdale, who he accused of doing a “disservice” to herself and the party with her leadership.

Unite general secretary Len McCluskey, in a dramatic intervention, also claimed the SNP could help keep a Jeremy Corbyn-led government in power after the next General Election, if there was a “progressive alliance” to oust the Tories.

He hailed a call by Scottish Labour deputy leader Alex Rowley for the party to ditch its “narrow” Unionist ideology and return to its Socialist roots – as reported in the Sunday Herald earlier this month – as a “clarion call” and the “correct thing to do,” adding: “Alex speaks a lot of sense”.

Speaking exclusively to the Sunday Herald during a visit to Edinburgh, McCluskey also attacked Dugdale for her role in the bid to oust Corbyn in UK Labour’s bitter leadership contest.

McCluskey, the UK’s most powerful union leader, threw his weight behind Rowley, who said the “status quo” of the Union dominated by Westminster could not deliver the radical social and economic change that left-of-centre Scots want to see.

McCluskey went on to say that as a Liverpudlian trade unionist, the issue of the UK Union had never been “uppermost in my mind” and that “solidarity with workers” north and south of the Border was of more importance.

He also said that “nothing should be off the table” over all constitutional options for Scotland, including independence and federalism for different nations and regions within the UK.

McCluskey said: “I think the whole question of independence is a question that has captured the minds of the Scottish people and therefore for any political party to be relevant it has to respond to that.

“The question of the Union is something from an English point of view that doesn’t necessarily occupy your mind.

“As a worker growing up in Liverpool it never occupied my mind. All that I know is that I have a strong affinity with the Scottish working class.

“The issue with the Union, the UK, is not uppermost in my mind. What is though, is the solidarity with workers whether it’s in Glasgow or Grimsby.”

The intervention came as recriminations continue to rage within Scottish Labour over Rowley’s statement, putting him at odds with Dugdale, when he said: “I have never considered myself a Unionist”.

Dugdale earlier this year declared that she had been “proud to vote No” in 2014 as she made a forthright defence of her Unionist credentials in an interview in the right-wing Daily Telegraph that ran with a headline of “Kezia Dugdale attacks Ruth Davidson and declares she is a ‘proud’ Unionist”.

McCluskey welcomed what he said was Rowley’s “call for the Labour Party to revert to its roots and to say to the Scottish people we are now effectively back on the right road”.

Speaking about Scottish Labour’s dramatic decline, McCluskey said: “I think Alex speaks a lot of sense. It is extraordinary what’s happened in Scotland. Of course we were told as long ago as 2007 when the SNP was targeting seats in the East End of Glasgow that they were beginning to be perceived as a more radical social democratic party then Labour.

“Unfortunately 2011 saw the SNP’s further advances and of course it’s been a steady move since. Last years’s [General] Election was like a tsunami.

“So Scottish Labour does have to take a serious look at itself and effectively say to the Scottish people that it is Labour on their side that speaks their language and that language has to be one of opposing austerity and supporting a fairer, more just Scottish society where working people receive the fruits of their labour. So the idea that Alex posed in the context of a Socialist argument, I think that was the correct thing to do.”

McCluskey, a leading trade union ally of Corbyn, added: “Whether you are for or against independence in Scotland, what you have to be for is a fair share of wealth for Scottish working people and at the moment Labour have lost their edge. So I think what Alex has been is saying, in fact I’ve been saying it myself, is that Labour has to recapture its radical traditions.”

McCluskey went on to suggest the SNP could help keep a minority Labour government in power if the Tories failed to win an overall majority at the next General Election and talked about the need for “pragmatism” under such circumstances.

McCluskey, whose union is UK Labour’s biggest financial backer, suggested an informal deal with Nicola Sturgeon’s party may be needed, something which has been firmly opposed by Dugdale.

He said: “I’m sometimes asked if I think Jeremy Corbyn can win the election and my answer is that that’s the wrong question. The question I ask is do I think the Tories will win the next election?

“I don’t think they’ll win the next election. They might be the largest party, but I do see Labour forming the next government not in coalition with the Greens or the SNP, but on the basis that Labour would be able to put together a Queens’ speech that the Liberals and SNP would be able to support.”

McCluskey added: “I can see in this political time, a huge time of upheaval a rejection of neoliberalism and of the status quo.”

In a further blow to the Scottish Labour leadership, McCluskey also suggested Dugdale had acted in an “un-statespersonlike” way with her support for the failed bid to oust Corbyn.

McCluskey said: “I thought Kezia was wrong and I thought it was inappropriate for her as leader of the Scottish Labour Party to make the points she made both before and during the election and indeed since the election.

“I’d have thought it would have been much more statespersonlike if she’d adopted a position like Carwyn Jones, the Welsh First Minister, who despite the fact that Owen Smith was a Welsh MP, stayed neutral. That’s what Kezia should have done and I think she’s done both herself and Scottish Labour a disservice.”

A Scottish Labour spokesperson, in response to the Unite boss, said: “Labour are the only party in Scotland who stand for what the majority of Scots want – a strong Scottish Parliament in the UK with close links to Europe. Labour are the only major party in Scotland who are willing to use the tax powers of the Scottish Parliament to invest in our economy rather than carry on the cuts.

“Kezia Dugdale and Jeremy Corbyn have been clear that there will be no Westminster deal with the SNP, whose obsession with independence would mean harder austerity in Scotland that would see the poorest lose the most.”

A Scottish Labour source added: “Like the majority of members in Scotland, Kezia Dugdale backed Owen Smith to be leader of the Labour Party.”