It is uncertain whether an independent Scotland would be able to retain the pound as its currency or would have to adopt the euro, a UK Government minister has warned.
Scotland Office Minister David Mundell said the matter was "one of the great uncertainties that surround the debate on independence".
The SNP has said if Scotland left the UK it would retain the pound and would only adopt the euro after a referendum, when conditions for this are favourable, but Mr Mundell argued that "no assumptions" could be made about currency.
He spoke out on the issue when he gave evidence to Holyrood's European and External Relations Committee. Tory MSP Jamie McGrigor asked if an independent Scotland would be "forced" into joining the euro.
Mr Mundell told him: "My understanding is the position is very uncertain, because the EU hasn't had to deal with the break up of a member state before and certainly no assumptions can be made about whether Scotland would be permitted to remain within the EU and not to join the euro.
"There are many academics who argue Scotland would require to join the euro unless it could negotiate an arrangement otherwise."
Mr Mundell, Scotland's sole Conservative MP, added: "I'm afraid from my perspective this is just one of the great uncertainties that surround the debate on independence."
He added that instead of debating how and when the independence referendum should be held, the UK Government would "rather move on to the substance of the debate around independence" and issues such as "Scotland's relationship with the EU, whether it would be able to be a member of the EU, whether it would be able to retain the various opt outs, and of course currency."
A spokesman for First Minister Alex Salmond said the "cast-iron position is that an independent Scotland will continue to use the pound".
He added: "The Scottish Secretary in the UK Government has said that Scotland can continue to use sterling, so the Westminster coalition is totally incoherent. There is absolutely no provision to make any member state join the euro."