The BBC have reported the following:
Zimbabwe's Prime Minister Morgan Tsvangirai has begun legal action against President Robert Mugabe over the appointment of regional governors.
Mr Tsvangirai says he should have been consulted over the appointments under the power-sharing deal which saw him become prime minister.
Mr Mugabe's allies have dismissed the claims.
The case is the latest sign of worsening relations between the long-time rivals.
South Africa's President Jacob Zuma, the mediator of the power-sharing deal, is due in Harare later to try to iron out the pair's differences.
"In my humble view, submission and plea, all of this is plain, clear and simple. Wherever the Constitution obliges the President to act in consultation with me as Prime Minister, he must first secure my agreement," Mr Tsvangirai said in court papers, reports the AFP news agency.
The BBC's Brian Hungwe in Harare says both leaders have been increasingly critical and outspoken about the failures of the power-sharing agreement - with both calling for an early election.
Last month Mr Mugabe said that the coalition deal should not be renewed when it expires in February.
They agreed to form a unity government after the country's economy collapsed following disputed elections in 2008.
A key part of the deal was to draft a new constitution.
But the process of agreeing a new constitution has been halted following repeated reports of political violence.
On Thursday, Finance Minister Tendai Biti told journalists that Zimbabwe had the finances to cover a poll next year.
"We have put money for elections, of course and for referendums," Mr Biti told journalists after presenting his 2011 budget.
However the winds of change were blowing and the USSR was doing what it always did best (In fact what it's current incarnation is still doing well) and that is training and equipping plus encouraging armed insurrection, terrorists and guerilla groups.
One such African group was led by Robert Mugabe who, while at Patrice Lumumba University in Russia, became firm friends with other "freedom fighters" in the ANC and forged links which have to date ensured non interference of any adequate kind from South Africa, who are the best nation to work with the people of Zimbabwe to restore democracy and freedom there.
Unfortunately the white farmers, for all their efficiencies, allowed themselves to believe for too long that they were impervious to change and were unprepared for Mugabe and his "freedom fighters" who, having won the country by force or arms then went on to completely bankrupt it by being similarly arrogant and inflexible.
But, why should we give a shit? What has it to do with us?
Well, the people of Zimbabwe are starving (Serves them right for keeping supporting Mugabe eh?) and are leaving and going to South Africa.
This is destabilising South Africa
We need a stable South Africa
We also need NOT to keep on pumping money into starving Africa.
IF Zimbabwe comes under decent sensible and prudent leadership it would not take long, 5 to 10 years, before it could once again be pumping out it's excess food into the rest of starving Africa.
Zimbabwe would not need foreign aid to sustain itself but instead would have a healthy bank balance and prosperous citizens. It could also revive it's defunct Tourist Industry for more foreign currency.
The pressures on South Africa would be lessened and with a boost for its own people and economy.
Starvation in the rest of Southern Africa would be less of a threat.
We would have to pay out less in foreign aid to Southern Africa.
South Africa's President jacob Zuma needs to get off his arse and help rather than posturing from the sidelines and playing to his ANC Gallery and the rest of us need to make some noise.