The government is prepared to give more money to the International Monetary Fund so that it can help struggling eurozone nations, the BBC has learned.BBC political editor Nick Robinson says such a move could mean debt-ridden nations like Greece, Italy or Spain are indirectly helped by British taxpayers.Prime Minister David Cameron is to meet G20 leaders in France to discuss the deepening debt crisis in the eurozone.He has previously ruled out direct UK contributions to any eurozone bailout.Our political editor said: "Chancellor George Osborne has reassured his backbenchers - and won himself favourable headlines in the Eurosceptic press - by declaring that Britain will not contribute directly to any eurozone bailout or allow the IMF to do the same."But he is ready to say that the IMF may need more funds to help struggling countries around the globe, which might of course just include a few in the eurozone getting money in effect from the British taxpayer."The UK currently provides £29bn ($46bn) of the IMF's £600bn ($950bn) lending capacity.Meanwhile, French president Nicolas Sarkozy and German chancellor Angela Merkel have warned that the next 8bn euro (£7bn) of rescue loans for Greece will be withheld until after a bailout referendum, expected in early December.The two leaders held talks on Wednesday evening with Greek prime minister George Papandreou to press him to end uncertainty about his country's future in the single currency.Last week Mr Papandreou announced a surprise referendum on the rescue package drawn up for Greece, indicating its referendum question would focus on whether or not to stay in the eurozone.Mr Sarkozy hopes to use the summit in Cannes to persuade cash-rich exporter nations like China to contribute to a one trillion euro (£870bn) European stability fund.On Wednesday, Mr Cameron told MPs that securing a eurozone deal was "urgent" for the global economy."It has become even more urgent to put meat on the bones of this plan to show that we're removing one of the key obstacles to global growth, which is the failure to agree a proper plan to deal with problems in the eurozone," he said.Labour leader Ed Miliband said: "As we saw in 2008, a global economic crisis can only be addressed by global economic leadership. There has been precious little of that in evidence in the past 18 months."Now is the time to turn the corner. To set out a plan that addresses the reality of faltering growth and rising unemployment - a plan that faces up to the G20 leaders' first responsibility: the responsibility to lead."