SCOTS Tory leader Ruth Davidson has compared the SNP with Ukip claiming both parties provide the same "bellicose, nationalist, anti-Westminster" option for voters.

Speaking at the launch of the Scottish Conservatives' European elections campaign, she played down claims that Ukip's likely success south of the Border would stregthen Alex Salmond's case for independence.

The SNP argues Ukip's strong showing in the polls south of the border, compared with Scotland where the party has failed to make an impact, is evidence of a diverging political culture in England.

But Ms Davidson said: "We may see a moderate increase in Ukip support in Scotland. But I think Nigel Farage has seen when he's been trying to campaign north of the border that his party has come somewhat late to things, in terms of looking for a niche for a bellicose, nationalist voice to be anti-Westminster and pedal in some grievance.

"That role has already been filled, I would have suggested."

She added that "in terms of anti-Westminster rhetoric and using that for political ends I think there is a similarity there" between Ukip and the SNP.

The Tories are on course to retain their single European seat in Scotland in the May 22 election, opinion polls suggest.

The party's top candidate is Dr Ian Duncan, a former head of the Scottish parliament's office in Brussels, who hopes to replace retiring MEP Struan Stevenson.

The party intends to put David Cameron's pledge of an in/out referendum on Britain's EU membership, if he wins next year's Westminster election, at the heart of its campaign.

Ms Davidson said: "We've already seen from polling that was done last year that the majority of people in Scotland want an in/out referendum, and that includes both a majority of SNP voters and Labour Party voters."

She cited polls showing most people wanted the UK to remain part of a reformed EU, adding: "In terms of where the people of Scotland are on this, that's exactly where the Scottish Conservatives are."

A UK-wide poll at the weekend put Ukip in the lead with 29% support ahead of Labour on 26% and the Conservatives on 23%.