In an effort to break the deadlock over a world trade agreement, Blair, delivering the annual foreign affairs speech at the Lord Mayor's Banquet on Monday night, called for a "comprehensive, ambitious agreement" to cut barriers to trade in agriculture, non-agricultural market access and services by the end of 2006.

"The European Union and the US must go further, within the negotiations, on agriculture. We must reduce trade distorting subsidies; we must see a credible end date for export subsidies; we must put an ambitious limit on the number of sensitive products that can be afforded extra protection," he said.

"In return, Brazil, India and others must move on cuts in industrial tariffs, services liberalisation, with proper flexibility for developing countries that need to sequence their commitments in line with their development needs."

"Agriculture accounts for under-2 per cent of the GDP of rich countries and roughly the same share of employment. Can we afford to allow differences over support for agriculture in rich countries to block an agreement that could give renewed hope to the 1 in 5 people in the world living on less than $1 a day?" he asked.

"Can we afford to weaken an international trading system on which future employment and prosperity in rich countries depends?"

The Prime Minister said that a one per cent increase in Africa's share of world trade would benefit Africa by over $70 billion, three times the aid increase agreed at the G8 summit at Gleneagles in Scotland in July.

He conceded that, as France argues, Africa could lose out in the short term if the proposed deal removed preferential trade agreements with the European Union. But he argued that in the long run, poor countries "stand to gain if we are bold, confident and ambitious."

Blair warned rich nations that they would enjoy "no security or prosperity at home" unless they "deal with the global challenges of conflict, terrorism, climate change and poverty."

Blair said the talks were an opportunity to tackle "some of the most fundamental injustices at the heart of world trade" and an opportunity to create the conditions in which millions of people will have a chance to escape poverty.

His speech came as a report by Oxfam warned that Blair's campaign to alleviate Africa's problems was doomed to failure. Phil Bloomer, a spokesman for Oxfam, said, "Tony Blair wanted this to be a year for Africa, but what's on the table now, if agreed in Hong Kong, would actually make the continent worse off."

At the Hampton Court EU summit last month, French President Jacques Chirac said that he would block a deal in Hong Kong rather than make deep cuts in Europe's farm subsidies.