Writing in The New York Times, Nobel-prize-winning economist Paul Krugman has warned the Scottish people to “be very afraid” of independence, as they go to the polling booths today.

He said: “Polling suggests that support for independence has surged over the past few months, largely because pro-independence campaigners have managed to reduce the ‘fear factor’ — that is, concern about the economic risks of going it alone.

"At this point, the outcome looks like a toss-up. Well, I have a message for the Scots: ‘Be afraid, be very afraid.’ The risks of going it alone are huge.

“Canada probably pays a price for its independence from the USA with lower labour productivity, but one of the reasons it remains prosperous and economically stable is because it has its own currency. Scotland would find it hard to maintain a separate currency in a highly integrated British market, but the SNP’s plan to keep the pound is a recipe for disaster.

“An independent Scotland using Britain’s pound would be in even worse shape than the euro-zone countries, which at least have some say in how the European Central Bank is run. I find it mind-boggling that Scotland would consider going down this path after all that has happened in the last few years. If Scottish voters really believe that it is safe to become a country without a currency, they have been badly misled.”

However, a ‘yes’ campaign spokesman said: "The Scottish Executive’s Fiscal Commission contains two Nobel Laureate economists — Joseph Stiglitz and Sir James Mirrlees — and they have published a hugely detailed report recommending sharing the pound as the best option for both an independent Scotland and the rest of the UK. That also means Scotland being in control of 100% of our revenues, rather than the current figure of 7%, enabling us to build a stronger economy and a fairer society.

“Scotland is in the top 20 of the world’s wealthiest countries. We are rich in terms of the skills of our people, entrepreneurship, innovation and technology, and we are blessed with an abundance of natural resources, including huge reserves of oil and gas and a quarter of Europe's renewable-energy potential.”