FACTBOX: What's next in Zimbabwe's election process

(Reuters) - Zimbabwe's opposition leader said on Saturday he would participate in a run-off election in the hope of unseating veteran President Robert Mugabe.

Morgan Tsvangirai, leader of the Movement for Democratic Change who emerged ahead of Mugabe in the first round on March 29, said he would contest the run-off only if international observers and the media had full access to ensure a fair vote.

WHEN IS THE RUNOFF?

The Zimbabwe Electoral Commission (ZEC) will set a date. By law, a second round should be held within 21 days of the result, published on May 2. However, the ZEC has the power to extend it.

WHAT OPTIONS DOES TSVANGIRAI HAVE?

Tsvangirai had raised doubts over whether he would take part in the run-off and has been out of the country since just after the vote, trying to keep up international pressure on Mugabe.

If he refuses to take part because his conditions are not met, then Mugabe would retain power. Tsvangirai said he would contest a second round only if it was monitored by international observers. Political analysts say Mugabe is unlikely to budge.

WHO WOULD WIN A RUN-OFF?

On the face of it, Tsvangirai would appear to be in a strong position to win a fair election. However, the opposition, human rights groups and Western countries accuse Mugabe of launching a campaign of violence and intimidation to try to secure victory in a second round.