Pressure for international action to combat the "silent tsunami" of the global food crisis intensified amid warnings that spiralling prices meant more than 100 million people could be plunged into hunger.
A Downing Street food summit called by Gordon Brown heard calls for the World Bank and International Monetary Fund to bring forward aid payments to countries worst hit as the first step towards a co-ordinated action by the G8 industrialised nations to tackle the worst food crisis for a generation.
Britain announced a £455m aid package, including £30m to the World Food Programme (WFP) and funding for research into food production methods.
The Government rowed back from its support for biofuels, announcing a review of the technology and warning that ministers would press for cuts in European biofuel targets if they are found to hit food prices.
Mr Brown said: "We need to look closely at the impact of biofuels on food prices and the environment." The European Commission also pledged nearly £100m to help the worst-hit regions. Estimates suggest that 25,000 people are dying daily from hunger, a crisis exacerbated by food prices that have hit their highest level since 1945.
Josette Sheeran, the executive director of the WFP, warned that food prices had pushed 100 million people into hunger and likened the crisis to the giant Indian Ocean tsunami that killed 250,000 people and left 10 million destitute. She said: "This is the new face of hunger – the millions of people who were not in the urgent hunger category six months ago but now are."
She called for an aid effort similar to the £6bn given to help victims of the 2004 tsunami.
The Prime Minister said that food shortages represented a crisis on a par with the global turmoil in the financial markets, and threatened the stability of nations. There have been food riots on Haiti and unrest in a string of countries including Egypt, Mozambique, Senegal and Indonesia.
Leaders in South America have also warned about the impact of biofuel production on food supply.
Mr Brown said that global problems of food supply were contributing to spiralling prices on British high streets. He said: "Hunger is a moral challenge to each one of us as global citizens, but it is also a threat to the political and economic stability of poor nations around the world. Riots now threaten democratically elected governments."
At Strasbourg, Louis Michel, the European commissioner for Development and Humanitarian Aid, told MEPs that the growing cost of basic food is "a worldwide humanitarian disaster in the making".
A report for the international affairs think-tank Chatham House said that a revolution in agriculture was needed to cope with a projected 50 per cent increase in the demand for food by 2030.
The report's author, Dr Alex Evans, said: "While the current focus on humanitarian aid is welcome, we need to be thinking now about the long term too – especially how to grow food supply and make sure that the process benefits rural poor people. What we're seeing now is the start of a multi-decade challenge."
Vicky Hird, Friends of the Earth food campaigner, said: "Food production must be revolutionised to prevent a global catastrophe. This means developing food and trade policies that put people and the planet first and abandoning damaging false solutions such as biofuels and GM."