Their marathon negotiations at Harare's Rainbow Towers Hotel capped nearly three weeks of talks by senior officials of Mr. Mugabe's Zimbabwe African National Union-Patriotic Front and both formations of the Movement for Democratic Change. Tsvangirai, MDC founder, heads the dominant grouping while Arthur Mutambara leaders the smaller formation.
Sources close to the talks said they were hanging in the balance after more than nine hours because Mr. Mugabe was refusing to make concessions handing over a significant portion of his powers to Tsvangirai. Mr. Mugabe claimed victory in a June 27 presidential runoff ballot, but that vote was widely denounced as illegitimate because Tsvangirai, leader in a first-round presidential March 29, had refused to participate over violence targeting his party.South African President Thabo Mbeki was working to bridge the gap between the two leaders in his capacity as mediator for the Southern African Development Community.
Sources said Mr. Mbeki was urging Mr. Mugabe to accept genuine power-sharing, which meant devolving significant powers to Mr. Tsvangirai as prime minister in what those close to the talks describe as a French-style balance of presidential and prime ministerial powers.
ZANU-PF sources told VOA that President Mugabe was prepared to work with Tsvangirai as prime minister, but refused to agree to give him executive powers to go with the post.
Sources said Tsvangirai and his MDC negotiating team were demanding significant powers as a condition of agreeing to a government of the normal five-year duration, failing which they would only agree to a transitional government of no more than 30 months duration.
Sharp disagreement led to the adjournment of the talks for an hour Sunday afternoon.
Critical issues on the table include the shape of the power-sharing government and how long it would last, as well the question of whether a new constitution would be required.
Correspondent Thomas Chiripasi of VOA's Studio 7 for Zimbabwe reported from Harare that the talks had been dragging on for hours with no end in sight.
Director Gordon Moyo of the Bulawayo Agenda, a civic group, cautioned that any pact which retains President Mugabe as executive head of state would negate any prospect of political and economic reform, and told reporter Ntungamili Nkomo that Zimbabweans would be "dismayed" if Tsvangirai were left playing second fiddle to Mr. Mugabe.