Billionaire investor George Soros has warned Scotland could not keep the pound if it became independent.
The Hungarian-born investor said it would not be "actually practical" for Scotland to keep its currency if First Minister Alex Salmond's campaign for independence was to succeed.
Mr Soros was once described as the "man who broke" Britain after making about $1 billion profit by selling sterling on Black Wednesday in 1992, when the UK crashed out of the Exchange Rate Mechanism.
He told the European Council On Foreign Relations in London yesterday: "Scotland wants to remain a part of the (pound) sterling and Britain is creating obstructions to that.
"It would be a very difficult relationship and I do not think Scotland becoming independent and yet remaining part of the sterling is actually possible."
The UK Government has previously ruled out a currency union with Scotland if people vote for independence from the UK in September's referendum.
Chancellor George Osborne, Treasury Chief Secretary Danny Alexander and shadow chancellor Ed Balls united in saying they would not support Scotland keeping the pound if there is a Yes vote.
Speaking at the launch of his new book, The Tragedy Of The European Union: Disintegration Or Revival, the now-retired Mr Soros, 83, said: "The alternative would be for Scotland to seek membership of the European Central Bank and then it would be part of the eurozone.
"I think an independent currency would be very inefficient and potentially dangerous."
Meanwhile, leading economists have queued up to say Mr Salmond must begin putting in place plans for a Scottish currency in the event of a Yes vote.
Out of five experts who appeared before a Scottish Parliament committee, only one believed a currency union was plausible and likely; three virtually ruled it out; and all five rubbished the idea that an independent Scotland should use sterling informally - so-called "sterlingisation".
The creation of an independent currency was therefore seen as the best option, either in its own right, or as a Plan B if negotiations with the rest of the UK to share sterling fell through.
Professor Ronald MacDonald, of Glasgow University, backed a separate currency as the best option.
He told the Economy, Energy And Tourism Committee that being part of a formal monetary union would not enable an independent Scotland to deal with "oil shocks" that come from the "resource curse" that could have "significant knock-on effects for competitiveness of non-oil sector".
He said: "Post-independence, the only option I can see for Scotland is a separate currency. Nothing else will work, nothing else will be credible to the markets."
Dr Monique Ebell, research fellow at the National Institute Of Economic And Social Research, said it would be "difficult to see how a monetary union would be in interests of the rest of UK," adding: "I would agree the most appropriate currency choice would be for Scotland to have its own currency, mainly because this would give Scotland the greatest capacity to react to shocks."
Sir John Gieve, visiting professor at University College, London, and a former Deputy Governor of the Bank of England, saw little likelihood of support from the the rest of the UK.
Professor Anton Muscatelli, the Principal of Glasgow University, and Professor Jeremy Peat, director at the David Hume Institute, made the case for a formal monetary union, with both economists stating a separate currency would be their second choice.
Professor Muscatelli said an oil fund could be used to help "smooth out public expenditure", solving the "hydro carbon problem" highlighted by Professor MacDonald.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article