France will walk away from this week`s G20 summit if its demands for stricter financial regulation are not met, the finance minister has told the BBC, according to BBC.
Christine Lagarde told HardTalk that President Nicolas Sarkozy would not sign any agreement if he felt "the deliverables are not there".
Strengthening financial regulation will be one of the key issues at the G20.
France wants a stronger global financial regulator than the US and the UK would like.
If France were to leave the summit, it would be a blow to both UK Prime Minister Gordon Brown and US President Barack Obama.
Both men have spoken of their high hopes for the meeting to stimulate international recovery.
"Leaders meeting in London must supply the oxygen of confidence to today`s global economy and give people in all of our countries renewed hope for the future," Mr Brown said.
Cracks emerging?
However, splits among other world leaders on how to tackle the economic crisis have also begun to emerge in other areas.
European countries, in particular, are resisting calls to commit to spending more this year and next.
President Obama is due to arrive in London for the summit later. It will be his first visit to Europe since he became president.
President Sarkozy has previously spoken out against "Anglo-Saxon" economies, as has the prime minister of Luxembourg, Jean-Claude Juncker.
"This crisis started in the United States. The Anglo-Saxon world has always refused to add the dose of regulation which financial markets, the international financial system needed," Mr Juncker said last week.
However, there have also been expressions of optimism.
German Chancellor Angela Merkel is reported to have said that chances were high that agreements - for example, to regulate hedge funds - would be reached.
