Michael Sata, the Zambian opposition leader, has launched a legal challenge, aimed at holding a recount of the presidential election results.
Sata lost the October 30 poll to Rupiah Banda, and has said that the election was a "fraud".
"I know that [my colleagues] are currently in court filing a petition. I am now working on some more documents which we will submit to the court next week," said Winter Kabimba, a lawyer for Sata's Patriotic Front (PF) party, on Friday.
"We are actually going for a vote recount which must be done by way of a petition."
Zambia has been one of the most politically stable nations in Africa. However, a prolonged election dispute and anti-government riots has caused fears of a political crisis in the southern African country.
Banda is due to hold a news conference on Friday at 1230 GMT and is expected to announce a cabinet reshuffle and outline economic policies.
A police official has said that a permit for PF supporters for a protest scheduled for Saturday was cancelled.
On Thursday, Zambian police had arrested 38 people after violent protests over the arrest of a priest and radio presenter in Kitwe, the country's second-biggest city, a police spokesman said.
Rioters attacked a police station, caused damage at a milling company, barricaded streets and set cars alight in Kitwe, 350km north of Lusaka, the capital.
Police also said that the arrest of Frank Bwalya, a priest and manager of Catholic-run Radio Icengelo, which has been critical of Banda's government, sparked the riots.
Levy Mwanawasa, the former presidnet, died in August, two years into his second five-year presidential term.
Mwanawasa was praised for his conservative economic management and anti-corruption campaign.
Banda had vowed to continue his policies, which kept growth at an average five per cent per year since 2002.