Theresa May warns of IndyRef2 danger on Scots campaign trail
Mrs May told STV news: "I've two reasons why the Conservatives can keep Stirling.
"Firstly because Stephen Kerr is a fantastic member of Parliament - a really strong voice for Stirling and for Scotland in the House of Commons.
"And second, because if you are Unionist and you want to want to stop indyref2, there's only one vote and that's Conservative."
The former Tory leader, who is standing again to be an MP in the election, said she was enjoying being on the campaign with Scottish colleagues.
Kerr's closest challenge is likely to come from the current Nationalist MEP Alyn Smith.