Zimbabwean opposition leader Morgan Tsvangirai has said participation in polls next year depends on the outcome of negotiations with the government.
Tsvangirai called for an end to political repression
Mr Tsvangirai leads one faction of the Movement for Democratic Change.
Recent elections in Zimbabwe have been marked by violence. The MDC split after a disagreement over whether to take part in the 2005 senate election.
Mr Tsvangirai said the president must end political repression and allow millions of exiles to vote.
"Those are our benchmarks for a free and fair election. We will not expect anything less in these elections," Mr Tsvangirai said at a rally held to mark the eighth anniversary of the MDC, in the southern Zimbabwean city of Masvingo.
"We want to participate, but we do not want a pre-determined election," Mr Tsvangirai said.
South African President Thabo Mbeki has been mediating in talks in South Africa between the MDC and the Zimbabwe government.
Mr Tsvangirai decided not to participate in elections for the senate in 2005, arguing that participation would only serve to give legitimacy to a system stacked in favour of the governing Zanu-PF party.
This caused a split in the party, with Arthur Mutambara later emerging as the leader of a faction that supported participation in the senate elections as a way of challenging the government.