Mugabe left the country on Saturday for Singapore where according to State media he was preparing for his daughter, Bona to start her graduate studies.
But speculation about his health heightened after the politburo meeting that was described as crucial by senior party officials was cancelled.
His absence also forced the cancellation of the Tuesday Cabinet meeting and that of inclusive government principals a day before.
After last week’s politburo meeting, Zanu PF’ spokesperson Rugare Gumbo said the party’s top decision body making wanted the emergency meeting to decide the future of the constitution making process.
“The politburo is meeting on Wednesday (April 5) to decide once and for all on the constitution,” Gumbo said then.
“(Zanu PF chief negotiators) (Patrick) Chinamasa and (Nicholas) Goche were given until (last) Friday to clear the parked issues (on the new constitution), otherwise we will ask our team to present the report on the outreach meeting to the principals.
“We can come up with our own draft constitution based on the report on the outreach meetings.”
Mugabe left after addressing the Zanu PF central committee meeting the previous day where he announced that the referendum on the new constitution will be held next month, failure to which the Lancaster House charter will be used to organise elections.
The 88 year-old Zimbabwean leader visited Singapore more than seven times last year where he was rumoured to be receiving medical treatment.
According to the United States diplomatic cables leaked by the whistle blower website WikiLeaks, Mugabe suffers from advanced prostate cancer that has spread to most parts of the body.
One of the cables quoted Reserve Bank governor Gideon Gono telling a US diplomat that a doctor in 2008 had given the Zanu PF leader five years to live.