Gordon Brown has said that former South African President Nelson Mandela will personally urge the world's richest nations to do more to help Africa.
Nelson Mandela has backed Britain's plan to tackle poverty
The Nobel Peace Prize winner will visit London in February to speak to the G7 group, Mr Brown said in South Africa.
Mr Mandela agreed to the visit during a private meeting with the UK chancellor at the Nobel Peace Prize winner's home.
Mr Brown is nearing the end of end of his tour of the African continent where he announced debt relief measures.
During 2005, the UK will hold the rotating presidencies of the G7, as well as the enlarged G8 which includes Russia, and the European Union.
On his visit to Africa, Mr Brown launched a campaign to persuade rich western countries to ease the burden of debt on the continent's poorest developing countries.
He has signed deals with Mozambique and Tanzania to take on 10% of their debt to international lenders, and promised to do so with 70 more among the world's poorest nations.
Speaking to the BBC, Mr Mandela applauded the UK chancellor's pledges and ideas for Africa which have been dubbed a "new Marshall plan".
"My first impression is that it is a good scheme and I wish more people would have a Marshall plan for Africa," he said.
Mr Brown told BBC News 24 that Mr Mandela is a hugely influential figure.
He said: "I believe there is growing support in the international community for the plans being put forward.
Mr Mandela "carries a huge authority around the world and I know when he talks to leaders in America, Europe or elsewhere he persuades them it's necessary to take action," Mr Brown went on.
"I think he wants to bring to their attention that the Marshall Plan is one way forward to be able to deal with the problems that he for his whole life has felt passionately about, that we take action to reduce infant and maternal mortality, tackle HIV/Aids and reduce poverty in many parts of Africa."
Mr Brown is also expected to announce plans to boost trade in poor countries when he and the Commission for Africa meet a number of the continent's finance ministers in Cape Town on Monday.
The commission has been set up by UK Prime Minister Tony Blair to tackle the economic problems facing Africa.
Mr Brown's South African counterpart, Trevor Manuel, who is also a member of the commission, has criticised international trade policies for favouring the world's wealthiest nations.
Speaking to the Sunday Times newspaper, Mr Manuel said "obscene inequalities" between rich and poor nations were widening.
'Change of attitude'
On Saturday, Mr Mandela attended the funeral of his last surviving son, Makgatho, who died of Aids, aged 54.
Mr Brown has been in Mozambique, where he announced debt relief
Mr Mandela said the stigma of Aids must be removed and it should be treated like any other disease.
He said: "The only way of doing so is to treat Aids as an ordinary disease like Tuberculosis.
"There was a time when we thought someone with TB was gone but today they can recover."
Mr Mandela added: "I am one of those who had TB who spoke openly and nobody stigmatises me for that."
The chancellor met children orphaned by Aids during his visit to Africa.
He said that money, better research and healthcare were not enough to tackle the disease and a change of attitude was required to end the stigma.