Zimbabwean opposition leader Morgan Tsvangirai has postponed his expected return home after discovering an assassination plot against him.

The Movement for Democratic Change (MDC) leader has been out of Zimbabwe for more than a month and had been due to return from Europe to contest an election run-off against President Robert Mugabe.

"We have received information from a credible source concerning a planned assassination attempt against President Tsvangirai. We are not in a position to say whether this threat concerns the actions of the state or a non-state actor," spokesman George Sibotshiwe said.

"In light of this information, and on the strong recommendation of Mr Tsvangirai's security adviser, it has been decided that the president will not return to Zimbabwe on Saturday," he said from neighbouring South Africa.

No one was immediately available for comment from the government or the police on the party's plot allegation.

Mr Sibotshiwe said the MDC was holding consultations "at a very high level" within the regional Southern African Development Community group over the issue, and that Mr Tsvangirai was keen to return home as soon as possible.

Mr Tsvangirai won the first round on March 29, but not by enough votes to avoid a second round against Mr Mugabe, who has ruled Zimbabwe for nearly three decades.

The March elections were followed by widespread violence, which the MDC says left at least 40 of its supporters dead and scores of others injured. It accuses Mr Mugabe's Zanu-PF party of a campaign of intimidation. Zanu-PF blames the opposition for the violence.

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