HARARE, Feb. 06 (Xinhua) -- Zimbabwean opposition leader Morgan Tsvangirai on Tuesday denied reports that he is critically ill in a South African hospital receiving cancer treatment.

"I am shocked to read in the press that I am in a critical condition," Tsvangirai said in a twitter post. "Of course I have cancer and not feeling too well but I am stable and the process is under control."

"I have been frequently on twitter of late, I am recovering," he said.

Local media on Tuesday quoted unnamed sources from Tsvangirai's family as saying that his health deteriorated rapidly on Monday and that he had lost appetite and had difficulty eating and swallowing fluids. He also reportedly had breathing problems.

There werer also reports that the Movement for Democratic Change leader and former prime minister is suffering from weight loss, exhaustion and muscle thinning.

Tsvangirai has been in and out of hospital since he disclosed in 2016 that he has colon cancer.

Last month, Tsvangirai hinted that he may retire from active politics, sparking fresh speculation on his possible successor and future of the opposition in the country.

His illness has also reportedly divided his MDC-T party as senior party members jostle to succeed him.

He has appointed one of his three deputies, Nelson Chamisa, to represent him in the MDC Alliance -- a loose coalition of seven opposition political parties that have united to contest against the ruling ZANU-PF party in elections scheduled for mid-2018.

The MDC Alliance has since started election campaigning, with Tsvangirai as its presidential candidate.

A former trade union leader, Tsvangirai once shared power with former president Robert Mugabe in a coalition government between 2009 and 2013.

His party has arguably been the major and biggest opposition party to emerge in post-independence Zimbabwe, posing the stiffest challenge to the rule of Mugabe, who resigned in November 2017 after military and public pressure.