Mugabe and opposition leader Morgan Tsvangirai signed a pact to form a unity government last September to try to end a post-election crisis, but a dispute over control of ministries delayed implementation of the deal.
On Friday, Tsvangirai’s Movement for Democratic Change (MDC) agreed to join the government.
The state-controlled Sunday Mail quoted Justice Minister Patrick Chinamasa as saying a constitutional bill creating the post of prime minister for Tsvangirai would be introduced in parliament on Wednesday.
"The bill, which seeks to give legal effect to the setting up of the proposed government, will be tabled before the house of assembly on Wednesday," the Sunday Mail said.
He said once passed, it would, on the following day, be transferred to the senate where it is expected to be approved.
Chinamasa said government was working to a timetable set down by regional Southern African Development Community (SADC) leaders at a summit on Zimbabwe last week, which called for the formation of the unity government by February 13.
The new government has raised hopes of rebuilding Zimbabwe’s shattered economy, where food and fuel is in short supply, unemployment is estimated at more than 90 percent and inflation was last calculated — in mid-2008 — at 231 million.
Africa’s deadliest cholera outbreak in 15 years has killed over 3,100 people and infected another 60,000.
South Africa and the African Union (AU), ahead of a summit of the continent’s leaders in Ethiopia, called for the United States and Europe to immediately lift sanctions on Zimbabwe.
"He (AU Chairman Jean Ping) calls on the AU member states that are in a position to do so and the international community as a whole, to provide the much-needed assistance to Zimbabwe to alleviate the suffering of its people and help the socio-economic recovery of the country," the AU said in a statement.
"In this respect, the Chairperson of the Commission underlines the need for the swift lifting of the sanctions imposed on Zimbabwe."
Tsvangirai defeated Mugabe in the first round of a presidential poll last March, but not by enough votes to avoid a run-off election, won by Mugabe after Tsvangirai pulled out citing violence against his supporters.
Under the deal, Mugabe will remain president, Tsvangirai becomes prime minister, while Arthur Mutambara, head of a splinter MDC faction, will be one of two deputy prime ministers.