Robert Mugabe vowed to go ahead with the presidential run-off today in the face of accusations that the vote would bestow upon him a 90 per cent mandate as meaningless as that which Saddam Hussein once enjoyed.

Addressing his last rally before polls open for the surreal one-horse race, Mr Mugabe told supporters that he would be magnanimous in victory and willing to talk with the opposition.

“Should we emerge victorious, which I believe we will, sure we won’t be arrogant, we will . . . say ‘Let’s sit down and talk’, and talk we shall,” he told the crowd on the outskirts of Harare. “So there it is, let the MDC reject it or accept it. We will continue to rule this country in the way we believe it should be ruled. This is an African country with responsible leaders.”

The renewed offer from Mr Mugabe came in spite of the insistence of Morgan Tsvangirai that the time for talking would be over if the election went ahead. In an interview from his hiding place at the Dutch Embassy in Harare, the opposition leader told The Times that as soon as Mr Mugabe declared victory he would become the illegitimate leader of Zimbabwe. “And I will not negotiate with an illegitimate leader,” he said.

Last night Zimbabweans, many of whom work far from home, were returning to their villages and townships after receiving threatening summonses from the ruling Zanu (PF) to report before the vote. Farm workers in Chegutu, southwestern Zimbabwe, said that they had been told to arrive at polling stations at 6am, an hour before voting begins, and stay there until after the results were posted.

“If there is one MDC vote they will find that person and cut off his or her head,” Ben Freeth, a white farmer quoted his workers as telling him. “ ‘It is a serious threat’ were the words that they used to tell me.”

The same message was delivered to voters in Chiredzi, in the southeast of the country, who were handed serial numbers of their ballot papers and told that their votes would be traced and punishment meted out if they were found to have voted the “wrong way”.

Mr Tsvangirai urged his supporters not to risk further harm and obey the instructions, with reassurances that the international community would never accept Mr Mugabe’s victory. Nigeria last night joined the chorus of African nations calling for a postponement of today’s vote. “They should go,” Mr Tsvangirai said. “If they even vote for Zanu (PF), if they even vote for Mugabe, what does that change? Even if he gets 90 per cent it’s not different from Saddam Hussein, 99.9 per cent of forced voting. What difference will that make?” he told the BBC World Service.

On Wednesday night more than 300 opposition supporters had taken refuge at the South African embassy in Harare, where officials were struggling to cope. “We don’t have any facilities to take care of these people, so we are doing our best,” Willem Geerlings, an embassy spokesman, said.

In past weeks victims of the political violence, which has claimed at least 90 lives, have taken refuge at the office for the Movement for Democratic Change in Harare. Police raids have left the opposition unable to guarantee them sanctuary. Mr Tsvangirai was forced to flee to the Dutch Embassy on Sunday night when armed soldiers arrived at his house.

His deputy, Tendai Biti, the MDC general secretary, has been charged with treason. Mr Biti was released on bail last night from prison, but had to surrender his passport. George Sibotshiwe, Mr Tsvangirai’s spokesman, fled to Angola this week after he spotted armed men approaching the safe house where he was staying. Other top opposition officials are also in hiding, including Mr Tsvangirai’s campaign manager. The party headquarters in central Harare was abandoned after a police raid this week.

The vote has been condemned as a farce after Mr Tsvangirai’s withdrawal because of the extreme campaign of violence and intimidation waged on his supporters. Mr Tsvangirai predicted that the vote would go ahead with maximum turnout. “There will be massive frogmarching of the people to the polling stations by force,” he said. “There could be a massive turnout, not because of the will of the people but because of the role of the military and the traditional leaders to force people to these polls.”

The chance that any monitors would be able to observe such abuses seemed distant last night. The independent election observer body of Zimbabwe, which fielded 50,000 observers in March, announced that it would be unable to monitor the poll because of the threat to its staff. A statement by the independent Zimbabwe Election Support Network (ZESN) said that it was “gravely concerned about the safety of its observers given the deliberate targeting”.

Mr Tsvangirai said that he would not leave Zimbabwe after the election — as he had threatened. “I will be here, I will be here and I’ll be watching Mugabe destroy himself. It’s now very clear that this man is self-destructing,” he said.

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