Prime Minister Gordon Brown has promised that the UK and other EU countries will "lead the way" in fighting "global financial turbulence".
Mr Brown pledges action to combat the financial upheaval
He told MPs that an EU summit at the weekend had agreed "co-ordinated action at a European and global level".
Tory leader David Cameron said the UK was suffering from not "putting money aside in the good years".
It came as an ICM poll suggested the Tories had a 13-point lead over Labour and were trusted more on the economy.
Markets have recorded heavy losses in reaction to the emergency bailout of US investment bank Bear Stearns.
The Bank of England has made an extra £5bn available for UK banks to borrow, as part of moves to ease credit fears.
Mr Brown said he had made clear at the summit that "while our economy is resilient and the fundamentals strong, we will at all times remain vigilant and - particularly at this time of global uncertainty - will continue to take whatever action is necessary to maintain economic stability".
He said Chancellor Alistair Darling was writing to members of the International Monetary Fund, G7 countries and the Financial Stability Forum to call for agreements on international action on transparency and disclosure, better risk-management and action on credit rating agencies.
Mr Brown also promised that EU countries would lead the way on combating climate change.
Mr Cameron said proper co-ordination by central banks was going to be essential in dealing with the financial turbulence.
He questioned whether putting the Financial Services Authority, rather than the Bank of England, "in the lead" was a good idea.
Mr Cameron added: "Spain's budget is in balance. Germany, the Netherlands, Denmark and Sweden all have budget surpluses.
"But Britain has the largest budget deficit in western Europe. Does the prime minister now regret that we're the one country that failed to prepare for the downturn by putting money aside in the good years?"
But Mr Brown said it was "very strange" that Mr Cameron, in comparing Britain with the rest of Europe, did not recognise "we have lower inflation than the rest of Europe".
He added: "We have a history of stability and growth and I think you'll find during the course of this year that the American deficit will be higher than the British deficit."
The prime minister's Commons statement came just hours before the ICM poll for The Guardian suggested support for Labour has dropped back by five points in the last month to just 29%.
Over the same period, the Tories have gained five points to 42%.
The size of Conservative support was being compared to that under Margaret Thatcher at the time of her third General Election victory in 1987.
Backing for the Lib Dems remained at 21%, suggesting that the Tories are winning support from Labour.
When pressed on which economic team they trusted most, 40% said David Cameron and his shadow chancellor George Osborne, while 32% named Mr Brown and Chancellor Alistair Darling.
ICM Research interviewed a random sample of 1,003 adults aged 18 and over by telephone between 14 and 16 March, weighting the results to the profile of all adults.