HARARE (Reuters) - Zimbabwe's main opposition party is discussing possible conditions for its leader Morgan Tsvangirai to contest a run-off election against President Robert Mugabe, a senior MDC official said on Sunday.
The Movement for Democratic Change has not yet decided whether to contest the second round, rejecting official results of the March 29 election showing the former union leader won with less than the outright majority he needed to defeat Mugabe.
But if Tsvangirai does not stand, it would automatically hand victory to Mugabe, accused by opponents of ruining Zimbabwe's once prosperous economy during his 28 years in power.
The MDC official said party leaders were hammering out conditions they would demand for Tsvangirai's participation in a second round -- including a strong international observer mission and the speedy release of results.
The opposition says the month-long delay in announcing the last result allowed the outcome to be rigged. The official result showed Tsvangirai won 47.9 percent of the vote to Mugabe's 43.2 percent.
One resolution being discussed by the MDC's national executive made clear a run-off was inevitable. It called on election officials to release the results of a second round within 48 hours and for Mugabe to concede defeat if he lost, the MDC official said. He did not want to give his name.
The opposition, which has accused Mugabe's ZANU-PF party of rigging previous elections, is also likely to demand an end to post-election violence it blames on Mugabe supporters.
"International supervision should be mandatory, the whole AU (African Union) should be allowed in. Over and above that there has to be an end to politically motivated violence," said the official, who attended a high-level MDC meeting on Saturday.
Neither Tsvangirai nor the MDC has endorsed the proposals despite growing pressure to announce their intentions.
"We are not convinced there is need for a runoff considering that our win was outright. In the very unlikely event of finding ourselves in a runoff, it will be a matter of burying ZANU-PF. We will win," MDC spokesman Nelson Chamisa told Reuters.
Mugabe, 84, has accepted the official results, and ZANU-PF says he will be its candidate on the second ballot.
According to electoral laws the run-off should normally be held within 21 days of the result, which was announced on Friday, but the electoral commission can extend the period. Political observers said a 40-day wait was likely.
On paper, Tsvangirai would be well placed to win given his first round victory and the expected support of Simba Makoni, a ruling party defector who came third in the initial vote.
But there are fears a run-off campaign could mean an escalation of political violence in a country where millions are struggling to survive because of a deep economic crisis marked by chronic food and fuel shortages and hyperinflation.
The opposition, Western governments and human rights groups have accused Mugabe of unleashing militias to scare Zimbabweans into backing him in the run-off. The government denies the allegation and says the MDC is behind political violence.
The opposition says at least 20 of its supporters have been killed and more than 1,000 homes burnt or destroyed by ZANU-PF militia since the elections.
The United States and former colonial power Britain have questioned the credibility of the first-round results and raised concerns about the legitimacy of another round of voting. Mugabe denounces his opponents as puppets of the West.
The United States and other nations have pledged billions of dollars in reconstruction aid if Mugabe is removed from power.