Johannesburg/Harare  - Zimbabwe's President and the Movement for Democratic Change of Morgan Tsvangirai remained at loggerheads Friday a day ahead of an emergency regional summit on the country's post-election standoff.

Tsvangirai on Friday again objected to taking part in a runoff presidential vote against Mugabe - as called for if no candidate takes more than 50 per cent of the vote - and reissued calls for Mugabe to step down.

In a statement the MDC leader said Saturday's meeting of the 14- nation Southern African Development Community (SADC) was "an historic moment for SADC and a defining moment for Africa."

"We can show the world that we, Africa, can solve our own problems and safeguard democracy and the rule of law," Tsvangirai said in a challenge to SADC members to break with their traditionally steadfast support for Mugabe.

"He (Mugabe) should recognize that he has lost and let me get on with making our great country great once more," Tsvangirai said.

Meanwhile, Mugabe's attendance at the summit appeared in doubt with state radio saying at the last minute he would not be in attendance.

In a sign of growing state defiance Zimbabwean authorities also banned political rallies, claiming they did not have the manpower to police them, state radio reported.

Thirteen days after Zimbabwe's elections the secrecy surrounding the official presidential results are fuelling tensions. The MDC claims Tsvangirai won outright. Mugabe's party says a runoff is needed.

In a BBC interview Tsvangirai said he could not be expected to partake in a runoff given that the electoral environment was not free or fair.

"In the provinces, in the districts, people are being beaten up," said Tsvangira, accusing Mugabe of deploying the military against opposition supporters and of interfering with the work of the Zimbabwe Electoral Commission.

Several ZEC officials have been arrested after being accused by Mugabe's party of rigging the vote in Tsvangirai's favour and the national election centre has reportedly been moved to a secret location.

Yet, Tsvangirai also appeared to leave the door open to a runoff, saying: "What we would expect is for SADC (the 14-nation to create conditions for that election to be conducted."

The 56-year-old former labour leader was speaking after his meeting Thursday with South African President Thabo Mbeki, SADC's mediator in Zimbabwe.

"It was a routine exercise of consulting and exchanging notes. Obviously they talked about the elections but that was not the purpose of the meeting," MDC spokesperson Nelson Chamisa told Deutsche Presse-Agentur dpa.

But another MDC source, who did not wish to be named, said Mbeki wanted to know what Tsvangirai expected from the SADC meeting.

Both Mbeki and Tsvangirai are expected at the meeting. Mugabe had been also expected to attend but state radio reports and remarks by deputy information minister Bright Matonga saying "one way or another Zimbabwe will be represented" appeared to point to a no-show.

Despite Zanu-PF's defeat in parliamentary elections and his party's admission that he did not win the presidential vote outright, Mugabe, 84, is trying to cling onto power.

Over the past week dozens of white farmers and at least one black farmer have been chased off their land by youth militia loyal to his party after Mugabe called on Zimbabweans to defend their land from "former colonizers."