The decision was made at a meeting of the Movement for Democratic Change's decision-making National Council which met on Friday.
Earlier in the day, a MDC official said that their leader Morgan Tsvangirai is expected to win his party's backing to join a unity government with the president's ZANU-PF when its executive holds a meeting on Friday.
"We are a democratic party, not just in name, but in practice. True, there are divergent views on the inclusive government, but once (Movement for Democratic Change) president Tsvangirai explains his position I'm sure the party will back him up," said the MDC official, who did not want to be named.
Tsvangirai has told a South African newspaper he has agreed to form a unity government with ZANU-PF, though his party voiced disappointment with the deal reached at a regional summit.
The contradiction suggested differences had emerged within the MDC over implementation of a September power-sharing pact, raising questions over whether a new Zimbabwean leadership would be united enough to tackle the country's economic crisis.
The agreement has been stalled by a long-running dispute over control of key cabinet positions.
The MDC official said that although there were sharp divisions over a power-sharing government, the leadership would eventually fall into line with Tsvangirai's position.
Political analyst Eldred Masunungure said that while Tsvangirai faced a test in his bid to steer the MDC into a unity government, his leadership of the party was not under threat.
"Tsvangirai is the central player in the national council," Masunungure said. "There may be dissent emanating from divisions between the pragmatists and hawks in the MDC, but there will be no rebellion and Tsvangirai's position will carry the day."
The power-sharing pact is seen as the best chance for Zimbabwe to rescue its ruined economy and stop a humanitarian crisis that has left over 3,000 people dead from a cholera outbreak and over half the population needing food aid.
In a desperate bid to arrest hyperinflation, President Robert Mugabe's government announced plans on Thursday to allow Zimbabweans to use foreign currencies, including the U.S. dollar, the South African rand and the British pound, for official transactions, though most Zimbabweans are paid in the local currency.