A month after he clinched a power-sharing deal between Zimbabwean President Robert Mugabe and his arch-rival Morgan Tsvangirai, former South African president Thabo Mbeki was back in Zimbabwe Tuesday to broker talks aimed at salvaging the accord.

Mbeki is to meet with Mugabe and Tsvangirai of the Movement for Democratic Change (MDC) about the deadlock between their parties on the formation of a unity government, as agreed in the September 15 deal.

Mbeki, who is accompanied by two negotiators, will also meet with MDC splinter faction leader Arthur Mutambara, who is the third party to the deal.

Under the terms of the agreement, Mugabe remains president and Tsvangirai becomes prime minister with the two sharing executive powers. Mugabe’s Zanu-PF is to get 15 ministries in a 31-member cabinet, Tsvangirai’s MDC 13 and Mutambara’s faction three.

Four weeks after the historic signing ceremony in Harare, the deadlock between Mugabe and Tsvangirai over the distribution of ministries threatens to sink the accord.

Mugabe on Friday unilaterally awarded control of the defence and home affairs ministries, among others, to his Zanu-PF. These portfolios give him control of the army and the police, both of which he has used against the MDC and its supporters for years.

European Union foreign ministers meeting in Luxembourg on Monday threatened to tighten sanctions against Mugabe and his allies unless he abandoned his hardline position.

Mbeki, who is mediating in Zimbabwe on behalf of the Southern African Development Community regional grouping, was met on arrival in Harare Monday by former labour minister Nicholas Goche and foreign minister Simbarashe Mumbengegwi, and not Mugabe, as on previous occasions.