Mr Blair, who was speaking in Edinburgh yesterday to mark 20 years of the Scottish Parliament, said that such a move on Mr Corbyn’s part would be a “major category error, both in principle and politically”.
He also said that it was now a “struggle” for him to vote Labour in elections, although he had always done so and was not “intending to vote anything else”.
A row broke out earlier this year within Labour ranks, after both Mr Corbyn and his shadow chancellor John McDonnell said they would not stand in the way of a second Scottish independence referendum should Labour win power at a general election – a move which was seen as attempting to win SNP support despite it being in direct contrast to the policy of the party in Scotland.
Scottish Labour leader Richard Leonard and Mr Corbyn later said that no Section 30 Order – the legal order the Scottish Government would need from the UK government to hold a referendum – would be granted in the early years of a new Labour government.
Outlining his fears about Brexit and its impact on the union, which he said would be used “persuasively” by Scottish independence supporters, Mr Blair was asked if Mr Corbyn should grant a Section 30 Order to “secure the support the SNP and keep the Tories out of power”,
He said: “I don’t think that Labour should give any indication at all that it’s prepared to put the Union on the table as some form of bargaining chip.
“This would be, in my view, a major category error, both in principle and politically. They shouldn’t do it. So, I don’t think that question should be answered at this stage. But I wouldn’t, I wouldn’t.... [I] think the question of whether there is another independence referendum has to be decided completely separately from questions of who forms the government of the UK.”
Pressed on who he thought would win, should there be another independence referendum, Mr Blair added: “I still hope and believe that the strength of the ties between Scotland and the rest of the UK will prevail.
“Even though I think Brexit – and particularly if we were to do a no-deal Brexit – adds a dimension of argument to the independence cause, at the same time you would have to say that if Scotland is part of Brexit, especially a no-deal Brexit, that will be a sufficient shock to its economy that you would think people would hesitate very long and hard before putting on top of that an additional shock.”Despite his disagreements with many of Mr Corbyn’s policies, Mr Blair said he had no intention of voting for any other party, but admitted he was conflicted.
“It’s a struggle I’ll be honest with you. And I’ve said it before, it’s a struggle,” he said. “Because I worry a lot about the direction of the Labour Party.
“I’ve found the debate and controversy over anti-semitism distressing - extremely distressing. And I think there is a sectarianism that’s been brought into the Labour Party that’s damaging.
“So, I’ve always voted Labour, despite all of the problems, and I voted Labour in the most recent European election and in the local elections. I’m not intending to vote anything else, but I repeat it’s a struggle.”
Earlier, Mr Blair said devolution was “one of the biggest things” his government had achieved. “It was a success because it was a policy we believed in, and we delivered it,” he said. “The fact that no-one disputes it now is a tribute to its acceptance, controversial as it was at the time. Has it laid to rest the claims to go further for full independence? Obviously not, but Scotland remains in the UK as of now.”
He added: “I remain a committed unionist. I want Scotland to remain part of the UK irrespective of Brexit, whether it does or doesn’t happen, but it would be foolish to deny that if what is proposed is a no-deal Brexit it would be a whole additional dimension to the argument for independence for those who wish independence, who would use it and use it persuasively.
“That’s why I continue to think that no Brexit is a better solution than no-deal Brexit.”
Mr Blair, who was born in Edinburgh and attended the private Fettes College, said his Scottish roots meant more to him “than is sometimes thought”.
He added: “I was born here, but more important than birth, which is an accident of circumstance and chance, my parents grew up in Glasgow, and coming back to Edinburgh I realise how much of my childhood was spent here and how many memories there are and how deep the roots go.”
He also reflected on his time as leader of the Labour Party, and at times his rocky relationship with Scottish Labour, but recalled it was the Scottish party which was the “first to vote for the new Clause 4 by the way, in case anyone has forgotten”.
He said that while the Labour Party had “moved further to the left than ever before in its history” it was still the “only serious contender for government”.
However, he believed that the extreme natures of Labour’s policies and Brexit, would push people to demand politics “more rooted in the rational centre” and “for a politics that’s less divided than the politics we have presently, for a politics that reaches for policies to unify.
“My belief is that it will be clear over these next months that there is potential for renewal for centre ground politics, I think that’s true for the UK as a whole and for Scotland as well.”
And he urged the Scottish Labour Party to use the departure of former Scottish Tory leader Ruth Davidson from frontline politics, as a way of capturing the centre ground.
“There’s a very open space for the competition for that centre ground vote,” he said.