UK Prime Minister Tony Blair is expected to push for a massive aid boost for Africa at this week's G8 summit in Canada.

Mr Blair has given his backing to a �4bn plan to rescue the world's poorest countries.

In the past, Mr Blair has promised to heal the "scar" of African poverty and - on a visit there earlier this year - he pledged a "new start" for the continent.

But his cash call is believed to have met stiff opposition in Washington and Tokyo.

Top of the agenda

US President George W Bush has already offered a $5bn boost in US foreign aid from 2004, if developing countries pledge to respect human rights and root out corruption.

Canada and the UK have been pushing for the EU and US to come up with half of the extra �8bn aid they jointly pledged at a UN conference earlier this year.

Negotiations between UK officials and the White House are reported to have been going on right up to the last minute in an effort to secure the best deal for Africa.

But it is thought Washington is reluctant to commit further funds and will want to spend its foreign aid unilaterally, rather than committing itself to a joint programme.

Meanwhile, Japan is scaling back its foreign aid programme in the teeth of a domestic recession.

Tony Blair has promised African aid will be at the top of the agenda when the leaders of the world's most powerful countries meet in Kananaskis.

He has thrown his weight behind a so-called Marshall Plan for Africa, named after the US programme that helped rebuild Europe after the devastation of the Second World War.

Under the New Partnership for Africa's Development (Nepad), countries will get aid and investment in return for better governance.

South African President Thabo Mbeki and five African leaders will join UN Secretary-General Kofi Annan in Canada to lobby G8 leaders to get behind Napad.

US sceptical

The US has infuriated some in Europe by pressing for World Bank aid payments to poor countries to be converted into grants.

Speaking to BBC News Online earlier this year, International Development Secretary Clare Short said such moves would "wreck" World Bank lending agreements.

The international "war on terrorism" is also likely to be high on the agenda in Canada.