PM Warns Of Labour-SNP 'Nightmare Scenario'

David Cameron has set out his reasons to vote Conservative in Scotland - saying a vote for either Labour or the Scottish Nationalist Party will mean a Labour-SNP coalition.

The Prime Minister was speaking at the conference of the Scottish Conservative Party in Edinburgh where he thanked party workers for helping to keep the UK together.

Tory activists were among those supporting the successful 'No' campaign in the Scottish independence referendum in September.

But, he said, the battle was not over.

"Friends - a major risk to Scotland's future remains. Miliband and Balls," he said, referring to the leader of the Labour Party and the shadow Chancellor.

"If you thought the ultimate nightmare scenario was a Labour Government? Try this: Labour and the SNP in Government.

"A unique, unprecedented coalition of the people who would break up our country and the people who would bankrupt our country.

"The only people who can stop them are us."

His comments came after the latest opinion polls in Scotland put the SNP between 10 and 28 percentage point ahead of Labour in second place.

The Tories trailed a distant third.

But analysis by Sky based on national projections in January had the SNP winning 53 seats in May's General Election with Labour on 282 - 44 seats short of an overall majority.

Mr Cameron said: "A vote for the SNP is a vote for Labour in Government . Nicola Sturgeon has made clear she is up for a coalition with Ed Miliband.

"So if you vote for anyone else apart from the Conservatives, you are voting for this outcome: Labour in Government.

"Ed Miliband in Downing Street and the very real prospect of Alex Salmond coming in through the back door."

Labour's shadow Scottish secretary Margaret Curran said: "David Cameron dreams of more SNP MPs than even Nicola Sturgeon does. He knows that every vote for the SNP makes it more likely he can hang on in Downing Street."

Sky's Deputy Political Editor Joey Jones, who has been a tour of the marginals that could prove key to the May result, said Mr Cameron has an uphill battle to convince Scots to back him.

On a visit to the "genteel and affluent" seat of Perth, he found the Conservatives had a lot of work to do.

He said: "If it were south of the border, Perth would be a dead-cert, true blue Tory seat.

"In the aftermath of the Scottish referendum, this was the sort of constituency Tories dared to dream might come their way.

"The problem for the Tories was evident, though. It is clear ... that the 'Tory bounce' many hoped for in the wake of the referendum campaign ... is, at this stage, proving elusive."