THERESA May has brushed aside Nicola Sturgeon’s claim that her legacy as Prime Minister will be Scottish independence, asserting confidence that the Union will be safe in her successor’s hands.

Ahead of Mrs May’s final speech as PM in Scotland this evening, the First Minister declared: “Scotland is heading inexorably towards independence; that will be Theresa May’s legacy.”

She also hit out at the "high-handed, arrogant and dismissive" attitude of the Conservatives over Brexit, which she claimed had shattered any illusion that the Union was a partnership of equals.

In response, the PM’s spokesman said: “Strengthening the Union has been an explicit priority for this UK Government. Today, the PM will set out how she is confident her successor will continue to make the Union their priority because as a union of nations and people we can achieve more together than we ever could apart.

“We will continue to stand up for the views of the majority of people in Scotland, who do not want another divisive independence vote.”

READ MORE: Nicola Sturgeon: independence will be Theresa May's legacy 

Asked if Mrs May, therefore, believed the Union was safe, he replied: “We held a referendum, which delivered a decisive verdict and the PM believes strongly and passionately that as a union of nations and people we can continue to achieve more together than we ever could apart.”

Whitehall insiders have stressed that the timing of the PM’s speech – just 24 hours before Boris Johnson and Jeremy Hunt attend the leadership contest’s Scottish hustings – is not coincidental and is meant to emphasise the need to “protect the Union,” particularly if Britain were to crash out of the EU without a deal.

In her speech today, Mrs May will say: "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.

"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."

One Whitehall insider described Mrs May's final speech in Scotland before her successor is named on July 23 as "inspirational," saying it presented a "heartfelt intellectual case for maintaining the Union".

READ MORE: 'Vulgar' English nationalism blamed for Scottish independence 

The PM is also expected to announce a snap review of whether Whitehall is doing enough to strengthen the Union after 20 years of devolution.

It will be undertaken by Lord Dunlop, the former Scotland Office Minister, and is due to begin next month. It will be handed over to the new occupant of No 10 in the autumn.