The Archbishop of York has urged Gordon Brown to end Britain’s ‘colonial guilt’ and spearhead a campaign of sanctions against the ‘racist’ dictatorship of Robert Mugabe.

In an outspoken intervention in which he says that Tony Blair’s ‘ethical foreign policy’ is a distant memory, Dr John Sentamu warns that Britain can no longer stand by while Mugabe follows the example of Idi Amin and destroys his country.

Sentamu writes in the Observer that Britain’s current approach, which is to regard Zimbabwe as an ‘African problem’ to be solved by its neighbours, has failed.

“The time has come for Mr Brown, who has already shown himself to be an African interventionist through his work at the United Nations 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 writes.

“The time for “African solutions” alone is now over. Despite his best efforts, President [Thabo] Mbeki [of South Africa] has failed to help the people of Zimbabwe. At best, he has been ineffectual in his efforts to… 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 was himself born in 1949 in a village near Kampala, the capital of Uganda.

In a passage that is likely to resonate in Africa, Sentamu likens Mugabe to the late Ugandan dictator Amin. Sentamu, who was imprisoned for 90 days by Amin after he had showed his independence as a judge, writes: “Mugabe is the worst kind of racist dictator. Having targeted the whites for their apparent riches, Mugabe has enacted an awful Orwellian vision, with the once oppressed taking on the role of the oppressor and glorying in their totalitarian abilities. Like Idi Amin before him in Uganda, Mugabe has rallied a country against its former colonial master only to destroy it through a dictatorial fervour.”

Sanctions, says the archbishop, should be modelled on the ones that were imposed on apartheid South Africa, “targeted… against those purveyors of misery whose luxury is bought at the cost of unbearable poverty”.

The Foreign Office last night said that there would be no change in the government’s policy towards Zimbabwe. Britain offers humanitarian help to Zimbabweans but is relying on Harare’s neighbours to take political action so as to avoid accusations that it is throwing its weight around as a former colonial power.

A Foreign Office spokesman said: “We are supporting people in Zimbabwe with aid… But it is clear from experience that there needs to be an African solution there.” Asked if the intervention by a former prisoner of Amin would persuade the government to change its line, the spokesman said: “He is entitled to his view.”

Sentamu’s intervention comes immediately after the resignation of Zimbabwean Archbishop Pius Ncube, a fierce critic of Mugabe, amidst a public scandal.