THE man who wrote the European Union’s now infamous Article 50 has warned prejudiced “short-sighted Little Englanders” are hemming in Scotland.

Former diplomat John Kerr - who devised the mechanism under which Britain is set to leave the bloc next year- has been campaigning for a second referendum on Brexit, the People’s Vote.

Citing the war dead of his own school, Glasgow Academy, the now Lord Kerr of Kinlochard made his most impassioned defence yet of Scotland’s place in Europe, saying Brexit was an “historic mistake”

Writing in The Herald, Lord Kerr said: “Scots of all parties and none should rally behind the People’s Vote cause.

“Glasgow and Edinburgh have long been great European cities. We mustn’t let short-sighted Little Englander prejudice hem us in.

“My grandfather was on the Somme. My parents met in 1930s slump Glasgow : their Hillhead home was blitzed in 1941. We should heed the lessons of history.”

READ LORD KERR IN FULL: Why Scots should rally behind the People’s Vote cause

Lord Kerr is channelling widespread concern about Britain’s diplomatic and security relationships post Brexit amid new threats, including Vladimir Putin’s to destabilise the West.

His remarks come after First Minister Nicola Sturgeon confirmed SNP MPs at Westminister would back a people’s vote. Lord Kerr said these votes could prove “decisive”. Prime Minister Theresa May opposes a second referendum.

This week Brexit Secretary Dominic Raab accused both Labour and the SNP of “political opportunism” in response to a Scottish Tory MP, Andrew Bowie, who told the House of Commons that only the Conservatives “respected the democratic will of the people.”

Lord Kerr said the people had a right to change their mind. He wrote: “Sixty-one per cent of Scots, and a rising majority in the UK as a whole, want a People’s Vote on the outcome of the current negotiations. So it was good to see the First Minister say on Sunday that SNP MPs would back such a Vote when the Westminster crunch comes. How Scots MPs vote could be decisive.”

A crossbench peer, Lord Kerr was Britain’s ambassador to the EU and US and a Foreign Office permanent secretary.