HARARE (Reuters) - Zimbabwe's main opposition leader and President Robert Mugabe's chief rival for the last 17 years said on Tuesday he has been diagnosed with cancer of the colon and is undergoing treatment in neighbouring South Africa.
Morgan Tsvangirai, 64, who was Zimbabwe's prime minister in an uneasy coalition government with the 92-year-old Mugabe from 2009 until 2013, said it was important for national leaders to disclose their health status.
Mugabe routinely denies local media reports that he is suffering from prostate cancer and says his frequent trips to Singapore are for routine medical checks.
"As a leader and a public figure, I have taken a decision to make public my condition," Tsvangirai said, adding that he had an operation last month and is on chemotherapy treatment.
"It is my firm belief that the health of national leaders, including politicians, should not be a subject of national speculation and uncertainty."
Tsvangirai, who lost the 2013 presidential vote against Mugabe, has since 1999 led the Movement for Democratic Change (MDC) but the party has, however, been weakened by splits over how to confront Mugabe's ZANU-PF.
The MDC chief, a three time loser to Mugabe, said although his condition was unfortunate, he intended to confront "this development with the determination to overcome it."
The MDC, evicted from the unity government after its crushing defeat in the 2013 election, is split over whether to dump Tsvangirai before the next vote in 2018. Critics say he has often been outsmarted by Mugabe, Africa's oldest leader.
The turmoil within the MDC has been a boost for Mugabe, whose ZANU-PF party has ruled Zimbabwe since independence from Britain in 1980 amid charges of rigging recent elections.
Mugabe, who intends to contest the 2018 vote at the age of 94, has denied rigging previous elections.
(Reporting by MacDonald Dzirutwe; Editing by James Macharia)