Gordon Brown accuses John McDonnell of falling into a “nationalist trap” on indyref2

Gordon Brown has accused John McDonnell of falling into a “nationalist trap” after he said a future Labour government would not block a second Scottish independence referendum.

The former Prime Minister said Labour should "stand up for Britain" amid a row over the Shadow Chancellor's comments on a fresh independence poll.

McDonnell sparked a backlash from MSPs and the leader of Scottish Labour this week when he said the party "would not block" a new vote on independence.

"The Scottish Parliament will come to a considered view on that and they will submit that to the Government and the English Parliament itself.

"If the Scottish people decide they want a referendum that's for them."

But Brown told The Sunday Times: "It is Labour’s role to stand up for Britain but sadly… Labour’s John McDonnell also fell into the nationalist trap by suggesting that a Scottish parliament should not be frustrated by what he termed the ‘English parliament’."

He added: "We have to emphasise the desire for autonomy with the need for co-operation across the UK. That means emphasising the importance of solidarity across borders and reciprocity between nations."

The comments came as the former PM warned that a no-deal Brexit would lead to "oblivion" for the UK's "precarious" union.

In a dire warning about the likelihood of a fracture between England, Scotland, Wales and Northern Ireland, the former prime minister said a no-deal Brexit could plunge the country into its "most serious constitutional crisis since the 17th century."

Writing in The Observer, he said Boris Johnson’s commitment to deliver Brexit "do or die" by October 31 was not in the national interest, but instead was driven by a "destructive, populist, nationalist ideology".

"If we are to understand why we are facing not only our most serious constitutional crisis since the 17th century but at the same time an unprecedented economic calamity precipitated by a no-deal exit from the European Union, we must recognise that nationalism is now driving British politics," he wrote.

The former PM added: "It follows that only thus – as an outward-looking, tolerant, fair-minded and pragmatic people – can Britain recover its cohesion and common purpose.

"These precious ideals could not survive the divisiveness and chaos of a no-deal Brexit. To prevent the rise and rise of dysfunctional nationalism the first step is to stop no-deal in its tracks."