Theresa May has called on Scottish voters to "strengthen the union" and boost her hand in Brexit negotiations by backing the Conservatives in the general election.

Speaking at a rally in Aberdeenshire, the prime minister pitched her comments firmly towards unionists, promising that backing the Tories as the country heads into talks over leaving the EU would benefit the whole of the UK.

"There is only one party that is committed to the union. There's only one candidate for prime minister who will stand up and defend the United Kingdom," Mrs May said, in what is her first campaign visit to Scotland ahead of the election in June.

"My commitment is clear, if you strengthen my hand in those Brexit negotiations I will work to ensure that Scotland and the UK flourish together."

Mrs May appeared alongside Scottish Conservative leader Ruth Davidson, telling the rally that a strengthened Conservative party would be "standing up against the separatists who want to break up our country".

The Conservatives hold only one seat in Scotland, but Mrs May hopes to improve on that in the June vote by courting Scots weary of the SNP's call for a second independence referendum and nervous about Labour's Jeremy Corbyn.

Mrs May has already turned down a call by Scotland's First Minister Nicola Sturgeon for a second independence referendum aimed at trying to protect Scotland's status in the European single market.

For her part Ms Sturgeon, speaking at a campaigning event in Glasgow, warned voters not to give the Conservatives a "free hand to do whatever they want to Scotland", saying the SNP was the only effective opposition to the Tories.