Bob Geldof has warned political leaders from the key economic powers - the G8 nations - that they must reach a deal to help Africa.
Bob Geldof is organising a string of concerts and a mass protest
The Live 8 organiser said not to do so would be a "grotesque failure".
Britain has the presidency of the G8 nations and is promoting a package of debt relief, aid and fairer trade.
A gathering of the nations' finance ministers is being held in London on Friday ahead of next month's major G8 summit at Gleneagles.
Britain has put Africa and climate change at the top of its priorities for the G8 and earlier this week the US and UK said they were close to a deal on debt relief.
Differences on aid
They propose to write off the debt of 32 countries, provided they tackle corruption and enact economic reforms.
The US has also promised $674m (£350m) in aid for Africa - but that was far less than Tony Blair had hoped to secure.
The prime minister had earlier said he planned to convince rich countries to add to their existing contributions - and help raise an extra $25bn (£13.5bn) in African aid.
Mr Blair and George Bush also failed to agree on taking action against climate change - another issue Mr Blair is hoping to highlight at the G8 summit.
On Thursday, launching a paperback edition of the Commission for Africa report in central London, Geldof said leaders in the West must not hold back on helping Africa because of corruption concerns on the continent.
"There are, of course, extremely corrupt governments in Africa, but there are very corrupt people in our part of the world - the difference is that we are rich," he said.
"Get off the corruption thing and force our governments to get there.
"There is a moral corruption to us signing our name on a document and never honouring it."
Earlier he said his Live 8 protests in Edinburgh to coincide with the G8 would be "a glorious failure" because world leaders will "probably not" agree to all his demands on African poverty.
Meanwhile, U2's Bono met European Commission leader Jose Manuel Barroso on Thursday. He told world leaders: "Don't blow it."
Bono and Geldof are spearheading the campaign to persuade the planet's most influential people to focus on poverty in Africa.
Geldof is staging five concerts across Europe on 2 July, four days before the leaders of the G8 countries meet in Scotland.
He is then hoping to mobilise a million people to travel to Scotland to protest.