Alex Neil: "Out of the frying pan into the fire."

Mr Neil told the Sunday Times lecture: "There is no point in us jumping out of the British frying pan of sterling into a federal European fire of the euro."

He claimed that joining the euro would limit the degree to which Scotland could be independent within Europe.

He said: "How can we in the SNP argue for full fiscal freedom from London if we are then prepared to hand back fiscal powers to Brussels and Frankfurt?"

The left-wing MSP said Scotland would not have a place at the top table in Europe.

He said that the governor of the Bank of England, Sir Edward George, would represent Scotland at the European Central Bank.

Independent monetary policy

Nor was there any evidence that joining the euro would increase Scotland's level of trade or ability to export more, he said.

"Scotland's unique position as the largest oil producer in Europe means the ability to pursue an independent monetary policy is critically important," said Mr Neil.

An SNP spokesman said the party had twice in recent years democratically decided its policy on the euro.

"We believe that the lower interest rates and stability offered by euro membership would benefit Scottish trade, tourism and inward investment," he said.

"The fact is that an independent Scotland in the euro would have 98% control over Scotland resources, compared to less than 10% as part of the UK."