Alex Salmond is facing fresh calls for clarity over his currency plans for an independent Scotland ahead of a second live TV debate on the referendum.
Scottish Liberal Democrat leader Willie Rennie said the First Minister must give more detail on what he dubbed the Nationalists’ “plan transition”.
The SNP dismissed Mr Rennie’s claims as “hypocritical nonsense” and reiterated the position that a formal currency union will be agreed with the rest of the UK in the event of a Yes vote.
That option has been ruled out by the three main parties at Westminster, with pro-Union campaigners increasing pressure on Mr Salmond to set out a ”plan B”.
Earlier this week, Crawford Beveridge, chair of the Fiscal Commission Working Group that advises the Government, said he considered sterlingisation – the use of the pound without any formal agreement – a viable transitional option.
Mr Rennie accused the First Minister of seeking to ” quietly build an exit strategy from his irreconcilable position”.
He said: “To exit from his Plan A and move to his Plan B, Alex Salmond has introduced his Plan Transition.
“He probably thought we didn’t notice him slip in the new phrase. But it would difficult to miss the two glaring flaws in this new strategy.
“Firstly, a transition by its very definition is a temporary mode. It is not a stopping place.
“Secondly, if Alex Salmond proposes that an independent Scotland temporarily use the UK pound like Panama uses the US dollar as a transition plan, what is it a transition to? The Euro? A separate Scottish currency?
“Independence is forever. But Alex Salmond’s currency plans now seem to come with an expiry date as short as six months.”
He highlighted the example of the short-lived currency union between the Czech Republic and Slovakia after the break-up of Czechoslovakia to argue that “the Salmond combination of a temporary plan and a vague destination will be catastrophic to the immediate prospects for Scotland”.
SNP Treasury spokesman Stewart Hosie MP said: “This is hypocritical nonsense from Willie Rennie, who of course stood on a manifesto commitment in 2010 to join the Euro.
“The fact is, it’s Scotland’s pound and we’re keeping it. It is in the overwhelming interests of both Scotland and the rest of the UK to continue to use the pound as part of a currency union – a position set out in detail by the Scottish Government’s Fiscal Commission.
“And of course a senior member of the UK Government was caught telling the truth when he admitted anonymously that ‘of course’ there will be a currency union.
“Instead of going around trying to frighten people in Scotland into voting No, Willie Rennie should ask himself why more and more senior Lib Dems, including former Edinburgh West MP John Barrett and former Highland Council leader Michael Foxley – are voting Yes.”