Mr Salmond has insisted that an independent Scotland would retain the pound, while Westminster has said it refuses to countenance a currency union. This would leave the country using it on an informal basis, and requiring its own reserves, as it could not rely on the Bank of England as a lender of last resort. Mr Carney said there would be “real fiscal costs” to this, while Andrew Tyrie, committee chairman, said Scotland would face a “very big shortfall” which would “almost certainly” be met by cuts or higher taxes.