THE SNP leadership has for the first time acknowledged that it could form a new UK Coalition with Labour in a bid to keep the Tories out of power, should the electoral arithmetic present the opportunity after next May's General Election.

With polls continuing to suggest a surge in Nationalist support at the next election with the party's number of MPs, currently just six, rising substantially, pundits are increasingly considering the possibilities of not only the SNP propping up a minority Labour administration but also of it forming a new Coalition with Ed Miliband's party.

Stewart Hosie, the Nationalists' deputy leader, said that if the SNP could stop the prospect of a Tory government bent on imposing more austerity on Britain "through whatever mechanism" and help a minority Labour administration, then it would want to ensure the right policies were pursued "for everyone across the whole of the UK".

Nigel Farage, the Ukip leader, has balked at the prospect of Alex Salmond becoming a UK Government Minister, saying "he could hold England to ransom".

But Mr Hosie pointed out how there was just one Tory MP in Scotland yet the nation's economy was run by the Conservative Chancellor George Osborne, saying: "I don't think it's right for people to whinge if, on a UKwide basis, we help form part of a government."

Asked if it would be right for the SNP to put Labour in power if the Tories had a majority south of the border, the Dundee MP replied: "Unionists can't have it both ways; that's the bottom line.

"They can't argue this is the Union, this is a family of nations and all the other stuff they say, and then start whingeing and whining when people from Scotland form part of a majority government. That just wouldn't do at all, would it?"

When it was pointed out how people in England and Wales might resent big decisions such as on Trident being made by a separatist party, the SNP's Treasury spokesman pointed out how the majority opinion in Scotland was against nuclear weapons being "parked 30 miles from our largest city".

Mr Hosie went on: "If we're in a position of such strength that we could scrap Trident and its replacement, saving £100bn the UK can't afford and making Scotland and, indeed, the whole of the UK less of a target, then it would be a good thing to do. It's a principled position we've held for a very long time as have many others, to be fair; that's a perfectly legitimate political decision to take."

On other issues, the SNP's deputy leader said that the Scottish Government had not sought to stir up resentment in England but introduce good policies for Scotland.

"Free education is a good thing; full stop. I'd love to see it in England if only the Labour Party could be progressive. We don't do good things in Scotland to stir up resentment...(but)because they are popular and necessary. I only wish there was a political party that represented the English people, who took the same view."

Meantime, the SNP leader Nicola Sturgeon welcomed new polling, which suggested the SNP holding the balance of power in a hung Westminster parliament with a minority Labour government was the most popular General Election outcome among Scots.

"With a strong group of SNP MPs holding the balance of power at Westminster, we can ensure that Scotland's voice is heard and use our influence positively to end austerity economics, free Scotland of Trident nuclear weapons, and secure the powers we need to build a fairer, more prosperous country," said the First Minister.

* David Steel, the former Liberal Party leader, has predicted a "kaleidoscope parliament" after the General Election with no party having an overall majority. "The Lib Dems and the SNP between them are more likely to hold the balance of power," he suggested.