ALEX SALMOND once suggested Scotland could benefit from joining the eurozone before the first independence referendum, as he argued the pound sterling was a "sinking stone".

Former SNP leader Alex Salmond said Scots may have to take to the streets to achieve independence, as Prime Minister Boris Johnson is determined to reject a second poll. He warned “peaceful street demonstrations” may be necessary to force the Prime minister to act, adding: “Any and all of these things are tactics to achieve the strategy.” Mr Salmond, who has enraged Scottish First Minister Nicola Sturgeon by setting up a new party, said he was willing to share a stage with her, but did not mean forgiveness.

His new Alba Party, launched on Friday, will only attempt to elect "top up" MSPs on the regional list PR system, in an attempt to win a “super majority” for independence at Holyrood.

But even if his plan proves successful, there are still many unanswered questions about what the SNP and his party would do next.

Should a second referendum happen, the separatists will be promising the loss of the fiscal transfer presently worth at least £10billion, the severing of Scotland from a UK single market worth almost 30 percent of its GDP, and above all, the financial chaos set to be unleashed by the SNP’s currency plan.

Even among separatists support for retaining sterling is high.

A recent poll found that, post-independence, 54 percent of respondents support using the UK’s currency permanently, with only five percent in favour of establishing a brand new Scottish currency.

Unfortunately for the nationalists, the Scottish electorate’s most unpopular currency option is also the most likely and the one the SNP are currently campaigning for.

To make things worse, if Scotland wants to rejoin the EU, it will almost definitely be forced to join the euro as well.

Before Europe plunged into a debt crisis, Mr Salmond suggested the benefits of Scotland entering the currency union.

In 2009, in an interview with Spanish television, Mr Salmond claimed there was a strong argument for his country to adopt the euro.

Mr Salmond had previously insisted that an independent Scotland would have kept the pound but, chuckling to himself, told his Catalan interviewer that sterling was "sinking like a stone".

The former first minister was conducting a round of interviews with the Catalan media during a visit to Barcelona, but at the time they were not broadcast in the UK.

However, the Daily Telegraph previously viewed the footage, in which Mr Salmond was asked about the surge in public support for former prime minister Gordon Brown following financial crisis of 2007-2008.

The former first minister claimed people were starting to question whether more could have been to help them if major economic decisions had been made in Scotland rather than Westminster.

He said: "And I think the argument for having strong fiscal powers, powers over revenue, powers to expand the economy within a monetary context, within a European euro context, will prove to be a very strong one for the people of Scotland.

"As you know, we're in sterling and sterling is sinking like a stone.

Mr Salmond's senior special adviser said the SNP had "always recognised the benefits of euro membership", subject to consent being given in a referendum.

He added: "There is no doubt that the plummeting pound and parlous state of the UK economy has caused many people in the business community and elsewhere to view membership favourably."

However, David Mundell MP, the former Shadow Scottish secretary, said: "It's becoming increasingly clear that the SNP will back the euro, which would have disastrous consequences for Scotland because you have a different currency from your main market, the rest of the UK.

"Most people find it absolutely bizarre that on one hand the SNP argue we cannot be run from London, yet are willing to give powers over our finances to Frankfurt."

A UK Government source added: "Alex Salmond has let the cat out of the bag. In the modern age it's foolish to believe you can say one thing when you are abroad and a different thing when you are at home."

In an interview with Chudonnews, constitutional historian Vernon Bogdanor explained why it would be extremely damaging for Scotland if it joined the eurozone.