Intensive diplomatic efforts were under way tonight to secure a face-saving exit for Mr Mugabe after 28 years as President of Zimbabwe amid increasing signs he was about to step down from power.

His closest cohorts informed him last night that he had failed to win an outright victory in the country’s weekend presidential poll.

Despite tampering with the results from the countrywide elections, the Zimbabwean Electoral Commission was set to announce that the main opposition leader, Morgan Tsvangirai, had taken 48 per cent of the vote, against 42 per cent for the 84-year-old incumbent.

The two men would therefore have to face a run-off poll in three weeks' time that Mr Mugabe has no hope of winning. "He considers this to be a huge insult, he is a proud man and needs an exit strategy," said a source close to the talks.

South Africa was leading the behind-the-scenes negotiations centring on a power-sharing deal that would see Mr Mugabe’s ruling Zanu (PF), which has ruled the country for 28 years, taking a vice-presidential slot.

Such a deal would also ensure that Mr Mugabe retained immunity from prosecution for any crimes committed in his authoritarian rule. "It is over for Mugabe. No one is now talking about him staying on, just somehow finding a graceful exit," the source added.

But a spokesman for Mr Tsvangirai's Movement for Democratic Change (MDC) denied that there were any negotiations going on. “I can confirm that there are no talks with Mugabe,” he said.

Observers doubt whether Mr Mugabe received 42 per cent of the vote but say even the biased electoral commission could not realistically swing any more votes his way. In addition, the veteran politician is aware that he would get trounced in any run-off poll.

Three days after the country's most important elections since independence in 1980, Mr Mugabe's Zanu (PF) party also appears to have lost control of parliament to the MDC.

The New York Times reported today that Mr Tsvangirai had been negotiating with Mr Mugabe's aides on a handover of power that would avoid the need for a second-round vote that would be "demeaning" to the veteran President.

The newspaper pinned its report on what it said would be a "stunning turnabout" on a Western diplomatic source and on John Makumbe, a political analyst. "The chiefs of staff are talking to Morgan and are trying to put into place transitional structures," Mr Makumbe said.

Mr Tsvangirai was expected to hold a much-delayed news conference later today.

In the absence of any clear news, tensions were continuing to rise. Riot police in armoured carriers patrolled two of Harare’s townships overnight and residents were told to stay off the normally bustling streets.

Results have been declared in only 131 of the 210 parliamentary constituencies. Zanu (PF) has a narrow lead of two seats over the MDC. A breakaway opposition party took a further five seats.

The Zimbabwean Electoral Commission insisted today that it would not be rushed, despite international pressure from Europe and the United States, and explained the delay in announcing the results on the complicated nature of the elections.

An independent monitoring group, the Zimbabwe Election Support Network, said that its projections gave Mr Tsvangirai 49.4 per cent, against 41.8 per cent for Mr Mugabe and 8.2 per cent for Mr Makoni – which was broadly in line with the Zanu (PF) predictions.

Marwick Khumalo, head of an observer group from the Pan-African parliament, said that the elections themselves were free, fair and credible overall and yesterday the African, Caribbean and Pacific (ACP) observer team also endorsed the polls.

"The ACP election observer mission was particularly impressed by the calm and peaceful atmosphere that prevailed before, during and immediately after polling day," the state-owned Herald newspaper quoted the ACP as saying.

Opposition activists have been clinging to the fact that results have been posted immediately outside local polling stations, saying that would make it more difficult for Mr Mugabe to rig the election – although they complain of up to a million ghost voters.

It is virtually impossible, however, for any organisation reliably to collate the information from all 9,100 polling stations, including some in the north that have been cut off by flooding, except for the Electoral Commission.

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