Alex Neil: "No seat at top table."

Mr Neil, who challenged Mr Swinney for the leadership of the party last year, said the high value of the pound means that entry at present would severely damage the Scottish economy.

He said: "I don't believe the SNP should support UK membership because by definition we would not have a seat at the top table.

"And our argument has always been that if an independent Scotland joined the euro we would have a seat at the top table.

"But if we join as part of the UK, Eddie George of all people - the governor of the Bank of England - would represent Scotland at the top table in the European Central Bank, and I think that would be very bad news for Scotland."

Mr Swinney said his party was having a democratic debate on the single currency, but he said the policy was to support membership of the euro under the correct conditions.

John Swinney: "Right economic conditions."

He said: "The last time we had a democratic debate about the single currency, the conference overwhelmingly supported the party's existing position of supporting Scottish membership of a single currency.

"It is subject to a referendum and subject to the right economic conditions being in place.

"I remember hearing that debate. It was a debate which was led in favour of the arguments for single currency by Andrew Wilson and by Alex Neil.

"So the debate may be going on the conference fringe but certainly on the conference agenda the SNP is very clear that it will support a single currency and will not be moving from that."