JOHANNESBURG, September 3, 2008 (AFP) - Zimbabwe's power-sharing talks deadlocked over President Robert Mugabe's desire to retain control of the country's security forces, opposition leader Morgan Tsvangirai said Wednesday.

'The talks deadlocked about a week ago after the (SADC) summit on the fundamental issue of executive authority,' Tsvangirai told independent Talk Radio 702 in his first in-depth interview on why the talks stalled.

A power-sharing deal put forward by mediator South African President Thabo Mbeki proposed that Tsvangirai become prime minister and that Mugabe retain the presidency in an inclusive government.

'But in this case,' said Tsvangirai, 'there was an attempt to fragment the cabinet, with some ministers reporting to the president and some ministers reporting to the prime minister.'

The deal would have seen economic and social ministries report to the prime minister and security ministries answering to the president which reflected Mugabe's lack of desire 'to dilute his power,' according to Tsvangirai.

The opposition leader added that Mbeki has said there were 'sufficient grounds' for the proposal to be signed but that 'he (Mbeki) is not the one who is going to sign'.

'I am going to be held accountable to the people. We are very conscious of our responsibility, of the burden of history, and we are not going to endorse something that does not resonate with the people.'

The MDC said earlier on Wednesday that it was up to Mbeki and the Southern African Development Community (SADC) which appointed him mediator, to decide the way forward.

Mugabe, 84, in power since independence in 1980, was re-elected in June in a one-man presidential run-off after Tsvangirai, victor in the first round, bowed out amid widespread electoral violence.