The City of London's most vocal "bear" has warned that the world is heading for a financial crisis as severe as the crash of 2008-09 that could prompt the collapse of the eurozone.

Albert Edwards, strategist at the bank Société Générale, said the west was about to be hit by a wave of deflation from emerging market economies and that central banks were unaware of the disaster about to hit them. His comments came as analysts at Royal Bank of Scotland urged investors to "sell everything" ahead of an imminent stock market crash.

"Developments in the global economy will push the US back into recession," Edwards told an investment conference in London. "The financial crisis will reawaken. It will be every bit as bad as in 2008-09 and it will turn very ugly indeed."