A leading Scottish Conservative has insisted they can "absolutely" overtake Labour and become Holyrood's second largest party in next year's elections.

It has been 60 years since the Tories beat Labour in a Scottish election, with the Westminster poll in 1955 seeing them return 36 MPs from north of the border, compared with 34 from Labour.

An opinion poll this week showed the number of people planning to vote Tory in May's Scottish Parliament elections had jumped six points to 18%, gaining significant ground on Labour, whose support remained unchanged at 20%.

Scottish Secretary David Mundell told the Mail on Sunday: "'I absolutely do think the Conservatives can overtake Labour at the next election."

He described Scottish Tory leader Ruth Davidson as the "de facto leader of the opposition" at Holyrood, adding: "She is the only politician in the Parliament who is able to go toe to toe with Nicola Sturgeon."

Mr Mundell said: "'I think the Scottish parliament election offers the opportunity for the Conservatives to be the second largest group."

A Scottish Labour Party spokesman said: "After the Chancellor's misguided budget statement the standing of the Tories in Scotland remains at rock bottom.

"David Mundell and Ruth Davidson might think they are the acceptable faces of the Tories in Scotland, but Scots know they are nothing more than representatives of Cameron and Osborne."