AN SNP victory at the General Election would mean Theresa May's opposition to a second Scottish independence referendum would "crumble to dust," Nicola Sturgeon has insisted.

The First Minister also raised the prospect of her party joining a progressive alliance to keep the Conservatives out of power in a hung parliament.

Surrounded by the SNP's 54 MPs at Westminster, the First Minister insisted she and her colleagues were "raring to go" to fight every seat in Scotland and that only the Nationalists stood between Scotland and an increasingly right-wing Tory government.

Ms Sturgeon, in London to open Scotland House, a business hub for the Scottish Government and development agencies in the UK capital, claimed her colleagues in the Commons had been the "real and the only effective opposition" to the UK Government.

"We intend to win this election in Scotland and for Scotland because now more than ever Scotland needs strong voices," she declared, saying victory was who received the most votes and the most seats and that if the SNP won, then this would be an endorsement of its policies, including on the holding of another independence vote.

The SNP leader accused the Prime Minister of putting party before country in calling for a snap election, pointing out how Mrs May had previously said that such a poll was the last thing the UK needed.

"Her motive is clear that as the terms of her hard Brexit become clearer the deep misgivings that so many people have will increase and grow. She has decided to act now to crush the parliamentary opposition that she faces. 

"The self-inflicted weakness of the Labour Party has given the PM her excuse but the SNP has a very different plan. We are determined Scotland's voice will be heard and heard loudly and clearly. Since 2010 we have seen the damage this Tory government has done, first with no majority of its own and then with a small majority. So we should be in no doubt what a Tory government with an increased majority would mean; it would mean not just the hardest possible Brexit but also further austerity and deeper cuts; it would mean damage to our precious public services and more pain for the vulnerable. And it would mean a rightward shift in the governance of the UK of a nature that just a few years ago Ukip could scarcely dream of. 

"So the SNP in this election, as we always do, will stand up for Scotland. A vote for the SNP is a vote to protect Scotland's interests. Only the SNP stands between Scotland and an increasingly hardline Tory government. It is a vote to end austerity and for investment in our public services. And it is a vote to ensure that the future of Scotland is decided not here at Westminster but in Scotland by the people of Scotland.

"Make no mistake: if the SNP wins this election in Scotland and the Tories don't, then Theresa May's attempt to block our mandate to give the people of Scotland a choice over their own future when the time is right will crumble to dust."

Asked if Ms Sturgeon would form a "coalition" with Jeremy Corbyn's Labour Party, she replied: "Let me say this very clearly and very straightforwardly, if the parliamentary arithmetic lent itself to the SNP being part of a progressive alliance to keep the Tories out of government, then the SNP would seek to be part of that as we said in 2015. Obviously, now, and this is one of the things that is different about 2015, I'm not sure there are many people who think Labour are going to be in a position on their own or with anybody else to form a government."

She added that her position was not to think about coalitions but to win as many seats and as many votes in Scotland as possible.