Zimbabwe's Prime Minister Morgan Tsvangirai has filed an application with the country's top court for a delay of elections to allow key reforms to take effect, court papers showed.
Tsvangirai wants the Constitutional Court to nullify a decree by President Robert Mugabe for polls to be held on July 31.
Mugabe had already, on June 19, asked the same court that Tsvangirai has approached, to push back crucial elections by two weeks to August 14.
But Tsvangirai, who did not specify when he wants the new elections held, has already said the two week extension that Mugabe sought is not enough.
Mugabe rushed to court in June, following pressure from regional leaders from the Southern African Development Community (SADC) bloc to shift the dates.
If Tsvangirai wins his case, he said the court will "prevent a legitimacy deficit which would plunge the country into further uncertainty," he said in court papers.
"Zimbabwe needs a break from the past," he said. "There have been electoral disputes since 2000 where outcomes have been contested largely because of the legal and political environment in which the elections are held."
"If granted, I genuinely believe that Zimbabwe will have a lasting, credible, free, fair and legitimate election whose outcome is not contested."
Tsvangirai who won the most ballots in the first round of the 2008 elections, said new elections should only be held after electoral laws reforms brought about by the new constitution, are implemented.
Tsvangirai said Zimbabwe's electoral commission should ensure a 30-day voter registration and inspection blitz before Mugabe announces new dates. Frustrating delays at voter registration centres has seen prospective voters waiting for hours in long queues.
In setting the original election date, Mugabe had said he was complying with the constitutional court's ruling to hold elections by July 31.
The elections will choose a successor to the uncomfortable power-sharing government, which was forged four years ago as a path away from a decade of political violence.
Tsvangirai has called for reforms -- to free the media, depoliticise the security services and make sure the electoral roll is accurate -- if the vote is to be credible.
Leaders from the SADC bloc meeting in Maputo two weeks ago issued an unusual rebuke of Mugabe, asking that he go back to the court and seek a delay.
They urged him to "create a conducive environment for the holding of peaceful, credible, free and fair elections".