Former Prime Minister Tony Blair said the UK must keep open the option of joining the euro if the current crisis is resolved.
Billionaire investor George Soros has called on Europe to start a fund to buy Italian and Spanish bonds, or risk the demise of the euro.
The Bank of England should pump £50bn more into the "stalled" economy to kick-start the recovery, David Miles has told the Financial Times.
The government cannot encourage people to save more, amid concerns a decline in spending could shut off the economic recovery, policy experts say.
World markets including the FTSE fell in early trading as weak economic data and Moody's downgrade of 15 banks unnerved investors.
UK banks including RBS, Barclays and HSBC are set to be downgraded by Moody's this evening, it has emerged.
The FTSE 100 fell alongside other major markets across Europe today, after the Federal Reserve cut its growth forecast for the US economy.
The Bank of England's Monetary Policy Committee (MPC) voted five to four to maintain quantitative easing (QE) at £325bn this month, overruling the governor and three colleagues who called for further expansion.
Governments across Europe are set to buy Spanish and Italian bonds through two European rescue funds, a move the ECB hopes will send a signal to financial markets that Germany is behind the eurozone.