ALEX Salmond has said there is an "overwhelming likelihood" that an independent Scotland could strike a formal deal to share the pound with the rest of the UK.

In an interview published today, the First Minister acknowledged his proposal for a currency union was not guaranteed in the event of a Yes vote.

Mr Salmond, who has repeatedly refused to identify his preferred "plan B" option, also said he was not scared by the prospect of creating a new Scottish currency if, as indicated by the UK Government and main opposition parties, the plan was blocked following a Yes vote.

His comments came as the Chief Secretary to the Treasury again ruled out a currency union, saying the proposal would limit an independent Scotland's economic policy choices and leave it "like a car without a steering wheel".

A new expert report, meanwhile, commissioned by entrepreneur Sir Tom Hunter, concluded that a currency union would be the best option in the event of independence but businesses would face "substantial extra" costs.

Mr Salmond's latest comments came in an interview with former Labour spin doctor Alistair Campbell in an interview with GQ magazine.

Asked if he could guarantee a currency union, he replied: "We can put it forward as the overwhelming likelihood and explain reasons why.

"It is the best outcome for us and for the rest of the UK."

Speaking after delivering a speech in Edinburgh, Mr Alexander said a currency union would not work for an independent Scotland or the rest of the UK.

He added: "That's not something that's up for negotiation or that's going to change. No one in Scotland should vote on the basis there is going to be a currency union because there won't be."

In his speech to business leaders Mr Alexander claimed there was "more evidence for the Loch Ness monster" than facts to support the SNP's economic case for independence.