The opposition in Zimbabwe has denied a deal has been signed with Robert Mugabe. A spokesman for the President claimed a power-sharing agreement had been reached with a faction of the Movement for Democratic Change (MDC) but cut out the party leader Morgan Tsvangirai. A senior official of Mr Mugabe's Zanu-PF said a deal had already been signed with Arthur Mutambara's MDC faction, however, a spokesman for that group said it was untrue. South African President Thabo Mbeki who is mediating talks says a deal has been reached but may not have been signed. Mr Mbeki said negotiations had not broken down and Mr Tsvangirai was still considering his position. He said: "We have dealt with all the critical elements on which President Mugabe and Mutambara agree, but there's disagreement with one element over which Morgan Tsvangirai has asked for more time to reflect." An agreement that sidelined Mr Tsvangirai could make it even harder to ease the crisis, which is a threat to regional stability, and to get Western countries to lift sanctions on Mr Mugabe's government. Talks on power-sharing began last month after Mr Mugabe's unopposed re-election in a vote that was condemned around the world and boycotted by Mr Tsvangirai because of attacks on his supporters. But three days of meetings in Harare have failed to reach an overall deal.