But Ms Sturgeon came under fire at First Ministers Questions today over the switch after proposing to keep the pound in the last independence referendum five years ago. The SNP voted to change policy at its conference in Edinburgh at the weekend which will see a new currency adopted after a Yes vote when six fiscal tests are met. The UK pound would continue to be used until this point.

But Tory interim leader Jackson Carlaw hit out at the switch. "In the independence referendum campaign just a few short years ago, the First Minister pledged we should keep the UK pound permanently, forever," he said. "Because in her words `that was in the best interests of Scotland.' "Yet this week, she and the SNP voted to ditch the UK pound." He added: "How on Earth is dumping the pound in the best interests of Scotland?"

SNP chiefs gear up for fight with activists over Scots currency

The Tory interim leader challenged Ms Sturgeon to name a single business or trade union which would endorse her plans to use a new Scottish currency. Ms Sturgeon set out plans for a second referendum on independence last week to be held late next year, but this has been rejected by Westminster. The new policy marks a change from the 2014 plan to retain the pound as part of a "currency union" with the rest of the UK. This plan ran into trouble when it was rejected by all the Westminster parties.

 But Ms Sturgeon insisted that an independent Scotland would continue to use the pound while it was in Scotland's interests until the conditions were right to "move to a different arrangement."

 She added; "That is the benefit of independence. We take the decisions that are right for our interests here in Scotland - rather than having the decisions, that are against our interests, imposed on us by Westminster."

 She called on Mr Carlaw to set out how much of its value the pound has lost against other currencies as a result of Brexit.

FMQs: Nicola Sturgeon defends plan to ditch the pound after Yes vote