World leaders are negotiating an increase in the International Monetary Fund's resources which could amount to hundreds of billions of dollars.
Chancellor George Osborne said the heads of state and finance ministers gathered for the G20 summit were now "getting down to the nitty-gritty" of discussing how to increase the size of the international economic backstop.
In remarks delivered on the sidelines of the Cannes meeting, Mr Osborne said that there was a "conversation about increasing resources to the IMF in the classic way".
Although he added that there were unlikely to be precise figures until at least end of the meeting on Friday, experts said that the IMF's resources may have to be doubled in order to make it big enough to calm markets.
The fund currently has \$950bn (£595bn) of resources, although more than half of this is either in use or has been committed to troubled countries.
The plans to increase the emergency fund have gathered pace amid concerns that the eurozone's own bailout fund, the European Financial Stability Facility (EFSF), is failing to inspire investors and calm markets.
Mr Osborne's comments came on a day which was dominated by news about the Greek government's U-turn on plans to hold a referendum on the latest stage of the bailout.
Despite speculation that Greek Prime Minister George Papandreou was on the brink of resigning, Mr Papandreou himself told Sky News that he would not stand down - though he would cancel the referendum plan.
The IMF increase will provoke controversy in the UK because it will indicate that Britain will be indirectly committed to providing further cash for bailouts.
However, the fund will not give directly to the EFSF, and the extra cash will not show up as a bigger UK deficit because of the way the contribution is accounted for.