The Archbishop of York, Dr John Sentamu, has made a direct appeal to Gordon Brown to intervene in the "humanitarian disaster" unfolding in Zimbabwe by imposing tough new sanctions.

Writing in the Observer on Sunday, Dr Sentamu refuted the assertion made by Tony Blair on his last visit to Africa as Prime Minister before stepping down as Prime Minister that Zimbabwe should be dealt with locally.

Dr Sentamu said: "Zimbabwe cannot any more be seen as an African problem needing an African solution - it is a humanitarian disaster."

He pointed to the current rate of inflation which stands at 8,000 per cent, empty supermarket shelves, and the "ravages of Aids ... exacerbated by government indifference" as evidence that the scale of the present emergency was enough to justify intervention.

Dr Sentamu said that the 'African solution' spearheaded by South African President Thabo Mbeki had failed to reverse the crisis in Zimbabwe and that a wider international response led by the UK Government was needed.

"The time has come for Mr Brown, who has already shown himself to be an African interventionist through his work at the UN in favour of the people of Darfur, finally to slay the ghosts of Britain's colonialist past by thoroughly revising foreign policy towards Zimbabwe and to lead the way in co-ordinating an international response," he said.

"The time for 'African solutions' alone is now over. Despite his best efforts, President Mbeki has failed to help the people of Zimbabwe. At best, he has been ineffectual in his efforts to advise, cajole and persuade Robert Mugabe to reverse his unjust and brutal regime. At worst, Mbeki is complicit in his failing to lead the charge against a neighbour who is systematically raping the country he leads."

The Archbishop said Britain needed to "escape from its colonial guilt" in the case of Zimbabwe and instead lead the way in securing targeted sanctions against "racist dictator" Mugabe, whose regime he equated to Idi Amin's brutal leadership in his native Uganda.

"While Mugabe may well brand Brown a 'colonialist' or 'imperialist' for any action he takes, the people of Zimbabwe look to us, and to others, to heed the cries of their suffering and the voices of our own conscience.

"We now all know. We cannot look the other way on Zimbabwe. Enough is enough," he concluded.