Mwanawasa, 59, was rushed to hospital last month after suffering a stroke before an African Union summit in Egypt and he has not left hospital since. Officials are discreet about his condition.

The Zambian leader's illness has fuelled speculation he might not be able to return to his duties and prompted demands that he be examined by doctors to determine his fitness to remain as head of the party and country.

Michael Mabenga, the MMD's chairman, told the state-run Zanis news agency that the party's national executive committee would soon convene to deal with the matter, pledging that members would be allowed to speak openly.

"The party feels that it is prudent to openly discuss the issues that have threatened to divide the party ... behind closed doors," Mabenga was quoted as saying. He did not say when the meeting would occur.

One junior minister in the cabinet has called for Mwanawasa to surrender the party presidency in order to ease his burden if and when he resumes state presidential duties.

Mwanawasa is a favourite of the International Monetary Fund and other Western donors, who extended billions of dollars in debt relief after he cracked down on government spending and launched an anti-graft drive.

An outspoken critic of Zimbabwean President Robert Mugabe, Mwanawasa chairs the Southern African Development Community which has mediated between the veteran leader and the opposition to try to end that country's political and economic crisis.

Mwanawasa, who suffered a mild stroke in 2006, could be forced to step down as Zambia's leader if parliament determined he was incapacitated. Vice President Rupiah Banda would then take over as acting president before elections were called.