Morgan Tsvangirai, Zimbabwe's prime minister, has been booed by a crowd of exiles after he pleaded with them to return home and help rebuild their country.

Tsvangirai gave a speech to an audience of 1,000 people in Southwark Cathedral in London on Saturday, saying that "Zimbabweans must come home".

In response, the crowd repeatedly chanted the same slogan, that 85-year-old Robert Mugabe, the Zimbabwean president, must quit first.

The crowd also booed Tsvangirai when he insisted that the four-month-old unity government of his Movement for Democratic Change (MDC) and Mugabe's Zanu-PF had "made sure that there is peace and stability in Zimbabwe".

Many people shouted "not yet".

Tsvangirai left the pulpit for two minutes before delegating a question and answer session.

Some exiles asked him what the government was doing to help Zimbabweans who had been "traumatised" by violence.

"If there is anyone who has been traumatised, it is me," he answered.

Alex Chigumira, 42, who fled Zimbabwe eight years ago, said: "We can already see that Tsvangirai has adopted the politics of Mugabe.

"He is unrealistic. What he forgets is that people here are traumatised, that is why they are in Britain."

Tsvangirai was in London on his final stop of a tour of Europe and the US aimed at gaining international support for a "new" Zimbabwe.

As part of his campaign, Tsvangirai earlier met British ministers and business leaders.

Tsvangirai is expected to hold talks with Gordon Brown, the British prime minister, on Monday.