Zimbabwe’s main opposition leader Morgan Tsvangirai is reportedly fighting for his life in hospital.
The 65-year-old is critically ill in South Africa, where he has been receiving treatment for colon cancer.
His supporters should “brace for the worst”, a source told Reuters news agency.
“From the medical report that I received yesterday the situation is not looking good,” the source said.
Mr Tsvangirai, who founded Zimbabwe’s Movement for Democratic Change (MDC) party, has been a key figure in opposing the country’s ousted former president Robert Mugabe.
Speaking last year, he claimed he had survived a number of assassination attempts and had been subjected to brutal beatings over the years.
His wife Susan was killed in a car crash in 2009, in which he suffered non-life threatening injuries.