Theresa May urges successor to strengthen Union as support for Scottish independence grows

‘I am confident that whoever succeeds me in 10 Downing Street will make the union their priority’

Theresa May is warning the two men vying to be her successor that one of their “first and greatest” duties as prime minister will be to strengthen and preserve the union of England, Scotland, Wales and Northern Ireland.

In comments which will be seen as a veiled swipe at Boris Johnson’s readiness to take the UK out of the EU without a deal against the wishes of a majority of Scots, Ms May will say that she expects her successor to make the the union “their priority”.

The prime minister will issue her call in a speech in Scotland a day before the first hustings north of the border between Mr Johnson and Mr Hunt in Perth on Friday.

It comes as opinion polls showed increased support for independence in Scotland, with first minister Nicola Sturgeon saying she wants a fresh referendum next year.

Mr Johnson came under assault in the House of Commons from the Scottish National Party leader in Westminster, Ian Blackford, who branded him a racist for a satirical poem he published as editor of The Spectator which described the Scots as a “verminous race”.

The Tory leadership frontrunner has insisted on his commitment to preserving the United Kingdom, stating that he will take on the title of “minister for the Union” if he enters Downing Street. He denied claims that he would cut funding to Scotland as PM.

Twenty years on from the creation of the devolved parliament for Scotland and devolved assemblies for Wales and Northern Ireland, Ms May will use Thursday’s speech to say that devolution has been a source of strength for the UK, not a sign of weakness.

She is expected to say: “I am confident that whoever succeeds me in 10 Downing Street will make the union their priority.

“He will be building on work done over the last three years, during which time strengthening the union has become an explicit priority of government.

“The job of prime minister of the United Kingdom of Great Britain and Northern Ireland brings with it privileges and responsibilities which you only really feel once the black door closes behind you.

Prime Minister Theresa May will stress the value of the Union in a speech in Scotland (EPA)

“One of the first and greatest is the duty you owe to strengthen the union, to govern on behalf of the whole United Kingdom, to respect the identities of every citizen of the UK – English and Scottish, Welsh and Northern Irish.

“And to ensure that we can go on facing the future together, overcoming obstacles together, and achieving more together than we ever could apart – a Union of nations and people.”

Ms May is also expected to announce a review of the way Whitehall departments deal with the devolved nations, to ensure official practice is keeping pace with developments in the legal framework for the relationship over the course of the past two decades.