He has also pledged to address climate change, despite America's refusal to sign up to the Kyoto protocol on cutting greenhouse gases.

Few doubt Blair's commitment on both issues but his belief that standing loyally with Bush -- through Afghanistan and Iraq -- was in Britain's national interest faces a severe test.

If he gets no payback from his US ally now, there will be upset. "He must cash in that political capital," one senior aid campaigner said.

With just a month to go until the leaders of the G8 nations meet in Scotland, London is frantic for progress.

Blair has already flown to Italy for talks with Prime Minister Silvio Berlusconi and will visit the leaders of France, Germany and Russia in the run-up to the Gleneagles summit.

"This visit is ... an opportunity for the prime minister to speak personally with President Bush about securing the progress we need to see on Africa and climate change at Gleneagles," Blair's spokesman said.

PRESSURE

The pressure to act was ratcheted up by Bob Geldof this week as he announced five star-studded concerts aimed at pressuring world leaders into eradicating African poverty.

The man who organised the 1985 Live Aid concert to ease famine in Ethiopia also wants protestors to lobby the G8.

"Eight world leaders in one room in Scotland on the 8th of July can save millions and millions of lives, but they will only do it if enough people tell them to," he said.

Geldof has expressed admiration for Blair's efforts. But if Britain's premier comes away empty-handed the abrasive Irishman and others will not be slow to lambaste him.

The Bush administration and other nations are unconvinced by Britain's plan for an "International Finance Facility" that would double aid for poor countries by issuing bonds against rich states' future aid budgets.

British government sources are now floating the idea of pressing ahead without US involvement.

Nor has London won a critical mass of support for a scheme to sell off IMF gold to fund further debt relief for Africa.

Trade reform, cutting barriers to African goods, also looks far from certain, not least as G8 member France has just voted against a European Union constitution, partly in protest at globalisation and free market economics.

"In the short-term more aid is needed, more debt relief is needed. But the big thing that is going to make a difference for Africa in the future is trade," said Andrew Pendleton of charity Christian Aid.