"There is a meeting tomorrow (Tuesday) to deal with the outstanding issues," Movement for Democratic Change (MDC) spokesperson Nelson Chamisa told AFP on Monday.
"It remains our fervent hope that the outstanding issues are successfully resolved followed by debate, passing and enactment" of a constitutional amendment to allow the formation of a unity government, he said.
The MDC decided on Friday to join a government of national unity with Mugabe, ending a protracted deadlock more than four months after signing a power-sharing deal.
The constitutional amendment is needed for MDC leader Morgan Tsvangirai and Arthur Mutambara, leader of a minor MDC breakaway party, to be sworn in respectively as prime minister and deputy prime minister next week.
Tuesday’s meeting of the Joint Monitoring and Implementation Committee (JOMIC), outlined in the September deals, will be presided by the three parties.
Some of the outstanding issues raised by Tsvangirai’s MDC are the immediate release of activists and opposition members, equitable allocation of key ministries and posts and the amendment of the constitution.
The amendment is set to be tabled in parliament on Wednesday, paving the way for a unity government amid calls from the African Union for international sanctions to be lifted to assist the stricken nation.
EU foreign ministers last week tightened sanctions on Zimbabwe, freezing the assets of companies based in British tax havens for the first time and adding 26 more names of people close to the Mugabe regime or their families to a travel-ban list, bringing the number to 203.