HARARE (AFP) - Zimbabwe anxiously awaited Monday the outcome of a legal bid by opposition leader Morgan Tsvangirai to force the declaration of poll results that could spell the end for President Robert Mugabe.

Tsvangirai, 56, has claimed outright victory in last week's presidential election but the ruling ZANU-PF says there is no clear winner and has backed 84-year-old Mugabe to win a sixth term in a second round run-off.

Tsvangirai visited South Africa Monday for private meetings, his first time out of the country since the March 29 presidential elections, a party official said.

"He is attending private meetings and going back this evening," exiled Movement for Democratic Change spokesman Roy Bennett told AFP, refusing to be drawn on the purpose of his meetings.

The visit by Tsvangirai, who has declared himself the outright victor of last week's presidential election, comes as MDC lawyers await the outcome of a legal bid to force the official declaration of the poll results.

A lawyer for Tsvangirai's MDC, which has won control of parliament in simultaneous legislative elections, argued before the high court on Sunday that the outcome was already known. "The results of the presidential poll were actually posted at polling stations at ward level," Alec Muchadehama told the court.

"After the poll was held on March 29, results were actually available on March 30." The electoral commission's lawyer however argued that the case was beyond the court's remit and Justice Tendai Uchena announced at the end of the hearing that a judgement would be made on Monday at 10:00 am (0800 GMT).

"A mooted presidential run-off ... is a sham," Tsvangirai wrote in a commentary in Monday's issue of the British newspaper The Guardian. "Our country is on a razor's edge," he warned, calling on South Africa, Britain and the United States to step up pressure on Mugabe and his supporters to stand aside.

State media reported Sunday that the ruling party had snubbed an approach from the MDC to form a unity government and was now demanding a complete recount of the presidential vote after detecting irregularities.

ZANU-PF is also contesting enough seats to regain control of the parliament. Mugabe -- who has ruled for 28 years since Zimbabwe gained independence from Britain in 1980 -- chaired a meeting of the ZANU-PF's politburo on Friday and was endorsed to compete in a run-off if neither of the two main contenders wins more than 50 percent of the presidential vote.

Meanwhile the war veterans, hardline Mugabe supporters who led the sometimes violent farm invasions at the start of the decade, tried to move onto several of the few remaining white-owned farms but most were later repelled by police.

While the election aftermath has so far been largely peaceful, the farm invasions served as a reminder of the violence which followed Mugabe's last electoral reverse when he lost a referendum on presidential powers in 2000. Mugabe, whose party has accused the MDC of planning to reverse the farm takeovers, called for Zimbabweans to protect their land from whites.

"Land must remain in our hands. The land is ours, it must not be allowed to slip back into the hands of whites," Mugabe was quoted as saying by the state daily Herald on Monday. Hendrick Olivier, chief executive officer of the Commercial Farmers' Union, said around five farms had been invaded by groups of war veterans in the southern Masvingo region.

Olivier said some of the so-called war veterans, many of whom were born after the 1970s liberation war, were still camped out late Sunday on two farms in the northeast and had ordered the owners to leave without their possessions.

Critics blame Mugabe's land reform programme, which was intensified after he lost the referendum in 2000, for Zimbabwe's meltdown from regional breadbasket to economic basket case.

Faced with 80 percent unemployment and six-digit inflation, almost one third of Zimbabwe's 13 million population have left the country, both to find work and food as even basics such as bread and cooking oil are now hard to come by.