The Prime Minister claimed to have struck a "historic" deal to end the global recession as he unveiled plans to plough more than $1 trillion into the world economy. "This is the day that the world came together to fight back against the global recession," he said. "Not with words but with a plan for global recovery and reform."

Barack Obama, the US President, hailed the deal as a "turning point" for the global economy which would put it on the path to recovery.

Under the $1.1 trillion (£750 billion) agreement, which followed several days of intense negotiation, struggling economies will be offered money provided to the International Monetary Fund (IMF) by wealthier nations. The G20 leaders also agreed restrictions on bankers' pay, rules to target tax havens and hedge funds and a new financial early warning system to prevent a future economic meltdown.

"Today's decisions, of course, will not immediately solve the crisis. But we have begun the process by which it will be solved," Mr Brown said. "I think a new world order is emerging with the foundation of a new progressive era of international co-operation,"

The success was echoed by Mr Obama. "By any measure the London summit was historic," he said. "It was historic because of the size and the scope of the challenges that we face and because of the timeliness and magnitude of our response."

Mr Sarkozy, who had threatened to walk out of the talks unless he got action on tax havens, said a "page has been turned" on the old financial model, the "Anglo-Saxon model".