Alistair Darling is scrambling to plug a gaping hole in the $1.1 trillion global rescue package agreed by G20 leaders in London — hailed at the time as Gordon Brown’s biggest success.

Some countries, led by Germany, are even calling for the bailout to be scaled back amid fears that it risks burdening economies with too much debt and could encourage inflation.

The breakdown of unity reflects the different speeds at which countries are emerging from recession and conflicting views about the outlook for the global economy.

The differences also extend to the kind of capitalism that leaders want to shape out of the global crisis. A serious disagreement will flare this weekend at a meeting in London of G20 finance ministers over whether to impose an international cap on bankers’ bonuses — a measure being pressed by France. Mr Darling believes that the proposal is unworkable and will table an alternative plan to tie bonuses to performance, The Times has been told.

At the end of the G20 summit in April, the Prime Minister claimed to have built a “new consensus” among world leaders and was lauded for his role in securing the rescue deal. But a follow-up summit this month in Pittsburgh will take place against the backdrop of undelivered pledges and wrangles over how to curb bankers’ pay.

Officials admit that almost $200 billion (£123 billion) pledged in credit facilities for the International Monetary Fund has yet to materialise. Most embarrassingly, the shortfall includes $75 billion due from the European Union. The Chancellor has warned Europe to set an example and do more to meet the target of $500 billion. Britain has agreed to lend up to $15 billion to poorer economies and is willing to provide up to $11 billion more as part of an EU package. So far, none of the extra credit has been called in by the IMF, although government insiders believe that it will be needed to prop up struggling economies before long.

Other European nations are resisting increasing their commitments to the IMF, demanding that China and India do more to shoulder the burden.

Germany is leading demands that the Pittsburgh summit start discussions on how to scale back the bail-out. Peer Steinbrück, its Finance Minister, has called for the reduction of fiscal measures as soon as possible. Angela Merkel, the German Chancellor, has echoed the call for an exit strategy. An insider at the Bundesbank, said: “I never walk into a room without knowing how to get out of it.”

British officials have barely concealed their irritation at what they regard as “premature” talk of winding up the global bailout. A senior official conceded that the global economy was picking up but added that it was “far too early to declare victory”. In a speech today, Mr Darling is likely to indicate that economic support already agreed, through lower taxes, higher government spending and lower interest rates, should remain until the recovery is “assured and sustained”.

Philip Shaw, chief economist at the investment bank Investec, said: “The authorities are aware that if they start exiting too quickly they run the risk of killing off any recovery. In the 1930s they tightened policy too early and it set everything back.

“The risk of leaving it too late is that you create an asset bubble, leaving interest rates too low for too long. That is precisely the sort of behaviour which sparked off the asset bubble that led up to the current crisis.

“The various governments are starting to talk about the need to draw up an exit strategy. It makes sense that since the bailout and stimulus packages were co-ordinated, the winding down of programmes should be co-ordinated too.”

Last night Mr Darling said that the biggest risk to global economic recovery was complacency and that it was too soon to withdraw stimulus measures. “My view is that the biggest single risk to recovery is that people think the job is done,” he told The Independent. He said that the situation was at a critical stage and added: “Banks must remember they were rescued not for themselves but to get credit going. They forget that at their peril.”

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