The focus of the global debate in the run-up to the Summit shifted to repairing the financial system as Gordon Brown called for called for a strengthening of financial regulation across the world and the US Government unveiled plans to buy up to $1 trillion of impaired bank assets.

US President Barack Obama said his Administration was 'working aggressively to stabilise our financial system' as he appealed to world leaders to use the London Summit on 2 April to take 'bold' action.

Prime Minister Gordon Brown urged leaders to 'remove uncertainty from the banking system to get lending moving again' in a speech to the European Parliament in which called for a strengthening of financial regulation and the extension of the regulatory net to encompass what has been termed the shadow banking system.

'Established limits to markets agreed in one country or region are being overtaken by global competition between all countries, and so I say it is not enough to promote self-regulation: we have to agree international standards of transparency, disclosure and - yes - of remuneration.'

The focus on financial regulation comes nine days ahead of the Summit in London's Excel Centre. On 22 March, Lord Malloch Brown, the Prime Minister's Envoy for the London Summit, said leaders were '75 to 80 per cent there' in terms of the outcome of the meeting.

In a widely-syndicated article published around the world, President Obama said: 'The leaders of the G20 have a responsibility to take bold, comprehensive and co-ordinated action that not only jump-starts recovery, but also launches a new era of economic engagement to prevent a crisis like this ever happening again.'

On the issue of reviving trade, he writes: 'We should embrace a collective commitment to encourage open trade and investment, while resisting the protectionism that would deepen this crisis.'

Mr Brown echoed both points in his address in Strasbourg, saying the biggest macroeconomic stimulus in history should be maintained until the world economy climbs out of recession, and warning against a return to 1930s protectionism. 'It is important that the world comes together to deal with this crisis,' he said.

Earlier the Prime Minister met the heads of 13 global banks including HSBC, JP Morgan Chase, Santander, Credit Suisse and Mitsubishi UFJ (see full list - word document 28.5KB) as well as the head of the Institute of International Finance (IIF), the global association of financial institutions, to discuss the industry’s view of the current economic outlook.

Bank executives heard the Government's views on reform of the financial services, plans for stabilising the markets, restoring credit flows and strengthening the financial system. The meeting also highlighted the need to reject financial isolationism and protectionism.

The IIF said a significant part of the discussion involved reforming the global financial system, including the development of macro-prudential oversight for all systemically important financial institutions, and greater convergence on international accounting standards.

The Prime Minister arrives in New York on 25 March for a meeting with UN Secretary General Ban Ki-Moon before continuing to Latin America where he will visit Brasilia, Sao Paulo and Santiago, where join U.S. Vice President Joe Biden, the presidents of Argentina, Brazil, Chile and Uruguay and the Prime Minister of Norway at the Progressive Governance Conference.