Bill Clinton today burst the bubble of optimism that the world's rich nations will make 2005 the year to tackle African poverty, saying that there was still no domestic pressure for American leaders to take action on the issue.

The former United States president, sharing a platform at the World Economic Forum with a star-studded line-up including Tony Blair, U2 singer Bono and Microsoft founder Bill Gates, said a fraction of the $80 billion spent on the war in Iraq every year would go a long way towards alleviating Africa's problems.

But he added: "Nobody will ever get beat for Congress or President for not doing it."

At an earlier press conference alongside Bono and Mr Gates, the Prime Minister said he was determined to use Britain's presidency this year of the G8 industrialised nations to secure a "quantum leap" forward in eradicating African poverty, which he described as "a scar on the conscience of the world".

Mr Blair also pledged a further £45 million towards the fight to tackle the spread of malaria in the continent. The extra funds will be used to buy mosquito nets, regarded by UN health experts as one of the most effective ways of reducing malaria, which kills 3,000 African children under age of five every day.

Mr Clinton pointed out that the American public had raised a "staggering" amount for the victims of the Asian tsunami and he now wanted to see that impulse transformed into regular assistance for the developing world. "We have never created an effective political constituency but it is coming," he said.

There was no senior Bush administration official to hear the panel's pleas, however. Unlike some previous years, the US has not sent a high-level delegation to the Davos meeting. Mr Gates, whose estimated $48 billion fortune makes him the world's richest man, this week pledged $750 million of his own money to support immunisation programs in developing countries. He told the discussion that the scandal of Africa was that so many of its problems were solvable.

"Millions of children die in Africa who shouldn't die, who it would be very easy to save," he said. "The fact that we don't apply the resources to the known cures or to finding better cures is really ... the most scandalous issue of our time."

Also sharing the platform in Davos were President Thabo Mbeki, of South Africa, and President Olesegun Obesanjo, of Nigeria.

President Obesanjo welcomed Mr Blair's Africa initiative, which involves the writing-off of African debt and the creation of a facility to raise development funding on international capital markets. But he said that the continent needed more direct aid: "We are not getting the critical mass of funds to make development possible."

The extra money announced by Mr Blair this morning joins a raft of additional British aid announced in recent days. Gordon Brown, the Chancellor, yesterday pledged almost £2.4 billion to combat poverty, including £1 billion to fund vaccines for children in the poorest countries.

Mr Blair said: "If what is happening in Africa today was happening in any other part of the world, there would be such a scandal, such a clamour, governments would be falling over themselves to do something about this."

He said that the African Commission, which he established with African leaders, would be making a series of proposals when it delivers its report in March, well ahead of the G8 summit at Gleneagles in July.

Bono - who appeared at last year's Labour Party conference - said that Britain's presidency of the G8 offered an "historic opportunity".

"I truly believe that the Africa Commission has the chance to change more lives," he said.

"I suppose my job as a rock star and activist is to bring applause when people get it right and make their lives a misery when they don't. I think I have some use here to try to encourage people to take some unpopular decisions at home and do the right thing on the global stage.

"These are expensive choices people have to make if they want to do the right thing for Africa."