Brown keeps up pressure on Mugabe

The meeting comes hours after the Prime Minister used shock tactics to secure backing for a tough stance.

G8 leaders issued a strongly-worded condemnation of Mugabe's "illegitimate" re-election as Zimbabwe's president and pledged tighter sanctions against his regime and the appointment of a United Nations envoy to mediate.

Mr Brown won unanimous support for the stances, including from Russians who are usually reluctant to interfere in such matters, after showing colleagues a photograph of the mutilated dead body of an opposition activist.

He said the joint statement, which rejected the legitimacy of any government "that does not reflect the will of the Zimbabwean people", was the "strongest" possible signal of international unity that change must happen.

The leaders of the group of leading industrialised nations - Britain, America, Canada, France, Germany, Italy and Japan - are gathered in a mountain-top hotel on Japan's northern Hokkaido island for their annual meeting.

In the statement they said they "deplored" the regime's decision to press ahead with the election despite "their systematic violence, obstruction and intimidation" which led to the pulling out of the only other candidate, opposition Movement for Democratic change leader Morgan Tsvangirai.

It urged the authorities to work towards a "prompt, peaceful resolution" that recognised opposition victories in the previous election in March and called on African leaders, such as Mr Mbeki, to continue efforts to broker dialogue.

And it called on UN secretary general Ban Ki-moon to appoint a special envoy to go to Harare to monitor the situation and support regional efforts to secure dialogue with the MDC.

A United Nations Security Council Resolution setting out the tougher stance, including financial and travel sanctions against Mugabe and close colleagues, is expected to be tabled soon by the United States.