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

(Reuters) - Zimbabwe said on Friday it would hold a delayed presidential election run-off on June 27 in which the opposition hopes to oust veteran leader Robert Mugabe after almost 30 years in power.

The long-awaited second round follows a disputed March 29 election in which official results showed opposition Movement for Democratic Change (MDC) leader Morgan Tsvangirai beat Mugabe, but not by enough votes to avoid a run-off.

WHAT WILL HAPPEN IN THE CAMPAIGN?

After weeks of uncertainty, Tsvangirai, who has been abroad since April 8 seeking to keep international pressure on Mugabe, has said he will take part in the run-off and will return to Zimbabwe on Saturday.

But police have banned a rally Tsvangirai was scheduled to address in Zimbabwe's second city of Bulawayo on Sunday. The opposition party has said it will challenge the ban in court.

Mugabe has said he would not allow what he says is a Western-backed opposition party to come to power.

HOW FAIR WILL THE VOTE BE?

Tsvangirai's MDC, civic groups and regional bloc SADC have said post-election violence in Zimbabwe has created conditions making it difficult for a free and fair run-off vote.

The opposition party says 40 of its members have been killed in political violence across the country, while thousands of homes have been destroyed. Mugabe and his ruling ZANU-PF party blame violence on the opposition.