Zimbabwean President Robert Mugabe has refused to give a passport to opposition leader Morgan Tsvangirai, despite a Sept. 15 agreement to share power in which Tsvangirai is the prime minister-designate.
Opposition officials said immigration officials refused to allow Tsvangirai to leave South Africa on Wednesday, the day he said his party would not continue the power-sharing negotiations until the mediator stepped down.
Tsvangirai accuses former South African President Thabo Mbeki of favoring Mugabe in the talks.
South African officials made an exception when Tsvangirai arrived for this week's talks on an expired emergency travel document. However, they could not allow him to travel to a third country, Ministry of Home Affairs spokeswoman Siobhan McCarthy said.
Opposition officials said Tsvangirai had managed to cross the border by road into Botswana, where officials were trying to organize an aircraft to carry him to Morocco.
They said Tsvangirai was to receive an award from Morocco's independent Amadeus Institute for promoting democracy through political dialogue.
Botswana's foreign minister this week called for southern African nations to close their borders with Zimbabwe to bring down Mugabe's regime - the strongest call yet for action from an African though it would be an unlikely development.
Meanwhile, two opposition officials said Friday they have reached provisional agreement with Mugabe's party on a constitutional amendment that would pave the way to forming the unity government.
The officials, in Harare and Johannesburg, stressed that there are many other outstanding issues that have not been agreed upon including the contentious division of Cabinet posts.
The opposition officials said agreement was reached after Mugabe's party removed clauses it had unilaterally inserted into the amendment, including one giving Mugabe sole power to appoint Cabinet ministers. Under the signed agreement, Mugabe appoints ministers in consultation with the prime minister.
The opposition officials spoke on condition of anonymity because of a media blackout imposed by Mbeki.
Mugabe's negotiator, Justice Minister Patrick Chinamasa, did not immediately answer his cell phone to comment.
The constitutional amendment would need to be passed by parliament to allow formation of a unity government and creation of the post of prime minister. Mugabe remains president under the agreement.