SIR Keir Starmer has made his first "mistake" by opposing a second independence referendum, according to one of the UK's leading political scientists.

Simon Hix, a politics professor at the LSE, drew attention to the Labour leader's stance on a new vote which Starmer set out in a briefing to Scottish journalists yesterday.

The position was set out after a poll last weekend put support for independence at 54% and found that 43% of Scots who voted Labour at the December General Election backed Yes.

READ MORE: Keir Starmer doubles down on Scottish Labour's indyref2 stance

The LSE politics professor wrote on Twitter today: "I think this is Starmer’s first mistake. I understand why he’s done it. But it’s high risk, given the trajectory of public opinion in Scotland."

Labour opposed indyref2 at last year’s General Election, but they said they would not block a referendum if Scots wanted one.

The caveat came after John McDonnell, the then shadow chancellor, used an appearance at the Edinburgh Festival to say a Labour government would not stand in the way of another vote. His intervention angered some Scottish Labour activists who believed he had imposed the policy without consultation.

The Scottish party this month clarified its position, saying they opposed indyref2 unconditionally. But the decision came after some senior figures in the party, including MSPs Monica Lennon and Neil Findlay, said the party should not oppose a second independence vote following the disastrous December election result.

During the Zoom briefing yesterday, Starmer, who made a promise during the leadership campaign to work closely with Scottish Labour, backed the new position: “There is nothing between me and Scottish Labour on this. One of the things I am determined to do as leader of the Labour Party is to ensure that the Labour Party across the United Kingdom and in Scotland are all speaking in the same way, on the same issues,” he said.

“The argument we have to make is about radical federalism, about putting power closer to people, and I don’t just mean in the Scottish Parliament, I mean beyond that, into local councils, into local communities.”

He added: “I don’t believe breaking up the United Kingdom is the right thing to do, particularly when we are on the verge of an economic crisis, the like of which we haven’t seen for a generation.”

Asked about the weekend Panelbase poll which showed 43% support for independence among Labour voters and whether he was concerned the party's unconditional opposition to indyref2 would lose them support, he said: “It’s for us to make the argument for a radical alternative, and that means not defending the status quo.

"Breaking up the United Kingdom when we are about to face an economic crisis, with probably mass unemployment, is the wrong thing to do.”