The front-runners are Vice President Rupiah Banda and Finance Minister Ng’andu Magande.
Zambia, which became a rare African success story under Mwanawasa, faces economic and political uncertainty as the race to replace him intensifies.
Senior Movement for Multiparty Democracy (MMD) officials met in the capital Lusaka to select a candidate for the election due in November after the death last month of Mwanawasa, who had ruled Africa’s biggest copper producer from 2001.
"They will look at a number of preliminary issues before voting and this will take quite some hours before we have a final decision," a senior MMD official said.
Officials said Banda and Magande have emerged as the favourites in the candidate vote — which is contested by 14 other MMD officials.
"The race is virtually between the VP (Banda) and Magande, although the VP has a slight edge from our assessment," a member of the MMD’s National Executive Committee, who asked not to be named, told Reuters.
Others in the frame are Home Affairs Minister Ronnie Shikapwasha, a former pilot, prominent lawyer Wila Mung’omba, a former IMF official, and Health Minister Brian Chituwo, a retired army officer and medical doctor.
The divisions within the ruling party could cost the ruling party ground to main opposition leader Michael Sata — who narrowly lost to Mwanawasa in 2006 presidential polls — particularly if infighting gets worse.
The MMD candidate will face a challenge from Sata, and Hakainde Hichilema, the leader of the United Party for National Development — which is the third largest party in parliament.
Investors hope Zambia’s new leadership will stick to Mwanawasa’s fiscal discipline, which won him praise from Western donors and billions of dollars in debt relief.
Some of the shine is also coming off Zambia’s economic performance. The kwacha has lost about three percent of its value against the dollar since Mwanawasa’s death, mostly due to political uncertainty although also the stronger greenback.