Star investor George Soros has said there will be "serious consequences" for the UK economy if the country votes to leave the EU this week.
Soros warned sterling would "decline precipitously" if the Vote Leave campaign triumphs in the EU referendum and said Brexit would be even more destructive than Black Wednesday in 1992, when Britain left the ERM - and Soros made a fortune betting against the pound.
Vote Leave said the UK would be more prosperous outside the EU.
The campaign's chief executive Matthew Elliott told the BBC: "The EU is costly, bureaucratic and blind to the impact it has had on people's wages and soaring energy bills."
In an article for the Guardian, Soros said that if Britain left the EU, sterling would fall by 15 per cent - possibly by more than 20 per cent - crashing to $1.15.
He wrote: "The value of the pound would decline precipitously."
"It would also have an immediate and dramatic impact on financial markets, investment, prices and jobs."
"I would expect this devaluation to be bigger and also more disruptive than the 15 per cent devaluation that occurred in September 1992, when I was fortunate enough to made a substantial profit for my hedge fund investors."
He described the idea that voters would not fell an impact on their personal finances as "wishful thinking."