Tony Blair is to call for a fairer deal for the world's poor, ahead of international trade talks in Hong Kong.
Mr Blair will address the Lord Mayor of London's banquet in the Guildhall
He will warn there will be "no security or prosperity at home" unless rich nations deal with poverty overseas.
The prime minister will make his plea in his annual speech on foreign policy at the Lord Mayor's banquet.
Mr Blair will argue that successful World Trade Organization talks, due to start on 13 December, could boost global trade by up to $600bn (£343bn).
Mr Blair will urge America, the EU and other trading blocs to stop protecting their own interests and make the concessions needed to help poorer economies.
With just four weeks until the WTO gathering, fears are growing the aims outlined by G8 leaders at Gleneagles earlier this year may not result in a meaningful deal in Hong Kong.
Poorer nations could gain $47bn (£27bn) if rich countries lowered trade barriers, while a 1% additional share of global exports would generate $70bn (£40bn) for Africa, the prime minister will say.
The Hong Kong summit will come at the end of Mr Blair's year-long presidency of the G8, during which he has endeavoured to put development issues and Africa at the forefront of the international political agenda.
In his speech, Mr Blair is expected to urge rich nations to focus on the big picture and recognise that the real choice facing the international community is whether it believes in an "open world" or a "closed world".
The prime minister will warn: "In a modern world there is no security or prosperity at home unless we deal with the global challenges of conflict, terrorism, trade, climate change and poverty.
"Self-interest and mutual interest are inextricably linked. National interests can best be advanced through collective action."
He will also recall the promises made at July's Gleneagles summit, which he chaired as president of the G8 group of rich nations, as well as aims outlined at the UN Millennium Summit in New York in 2000.
These meetings led to the agreement of a set of goals to improve the lives of people in the world's poorest countries.
"At Gleneagles we showed the world - and the world's poor - that political leaders in rich countries not only care about world poverty, but are capable of acting together to help eliminate it," the prime minister will say.
"Of course we could have done more, but we showed that co-operation can deliver results - real results to increase aid, cancel debt, fight Aids and malaria, invest in free health and education, combat corruption, and build Africa's capacity to keep peace".
He will say the challenge now is to extend that principle of co-operation into the multilateral trading system.
"Sometimes I worry that we lose sight of what is at stake," he will say.
Mr Blair is expected to stress everyone stands to benefit from a successful conclusion the round of talks in Hong Kong.
He will point out that the previous Uruguay round of talks generated $500bn (£286bn) a year in international trade and a new agreement that cuts trade barriers by one-third could boost the world economy by $600bn (£343bn).