Zimbabwe PM Morgan Tsvangirai wants Mugabe 'divorce'
Zimbabwean Prime Minister Morgan Tsvangirai has called for a "divorce" from his national unity government colleague President Robert Mugabe.
Mr Tsvangirai organised a news conference after his ally, Energy Minister Elton Mangoma, was arrested.
He said the relationship between the parties had broken down and called for elections to be held.
Former foes Mr Mugabe and Mr Tsvangirai joined in a unity government two years ago after a disputed election.
But Mr Tsvangirai told the news conference: "We have reached a moment where we are saying, let's agree that this is not working, it's dysfunctional.
"If people find that a marriage has reached irreconcilable differences, they agree to a divorce."
He said elections should be held under the auspices of Sadc (Southern African Development Community).
Mr Mugabe has also called for elections, saying the unity government no longer works.
Mr Tsvangirai's Movement for Democratic Change (MDC) has previously said elections should wait until a new constitution was in place and said poll would lead to renewed violence.
Mr Mangoma, a founder of the MDC, was taken from his offices by three plain-clothes police on Thursday.
A police spokesman could not confirm whether Mr Mangoma had been arrested or was just being questioned, and no reasons were given for his detention.
Reports say the arrest is believed to be in connection with a fuel deal the minister made in December with a little-known South African company.
MPs from Mr Mugabe's Zanu-PF party accused Mr Mangoma of bypassing tender procedures and also claimed that only a fraction of the fuel paid for had actually been delivered.
He denies any wrongdoing and says all the fuel was delivered.
The MDC and Zanu-PF agreed to share power after disputes over the 2008 election which saw many thousands of MDC activists forced from their homes by pro-Mugabe militias.
The MDC won a majority of seats in parliament but Mr Tsvangirai pulled out of the presidential run-off, saying he wanted to save his supporters' lives.
Separately, the Supreme Court has nullified the election of MDC chairman Lovemore Moyo as speaker of parliament, following a legal challenge by a close ally of Mr Mugabe, Jonathan Moyo (no relation).
Jonathan Moyo argued that the 2008 election of his namesake was chaotic and disorderly, reports the AFP news agency.
Roy Bennett acquitted
The Supreme Court also ruled that treason charges against senior MDC official Roy Bennett be dropped.
He was arrested in 2009, after he had been named as the MDC's nominee as deputy agriculture minister in the unity government.
He is a white farmer whose land has been seized under Mr Mugabe's land reform programme.
He told the BBC that he is unlikely to be able to take up his ministerial post as two further charges of contempt of court and perjury have been brought against him in what he says is a campaign of intimidation led by Zanu PF.
In 2004, he was jailed for pushing a Zanu-PF minister in parliament.