Ghana's Supreme Court will on April 16 begin hearing a petition challenging President John Dramani Mahama's election last December.
Losing New Patriotic Party (NPP) Nana Akufo-Addo and two others filed the petition on December 28, two weeks after Mahama was declared winner of the polls.
On Tuesday, the Supreme Court also ordered the applicants to file affidavits of all witnesses they intend to call during trial within seven days.
Mahama who is also the leader of the National Democratic Congress (NDC) and the other respondent in the case Electoral Commission chairman Kwadwo Afari-Gyan were given five days to respond.
In order to fast track the trial, the court said the parties may be allowed to give oral evidence and where there are compelling reasons it would give orders for witnesses to testify.
The hearing of the substantive case was delayed following disagreements on both sides.
The court is expected to establish whether or not there were violations, omissions, malpractices and irregularities in the conduct of the presidential elections and whether the outcome could affect the results declared by the Electoral Commissioner.
Mahama was sworn in as President on January 7 in line with the country's constitution.
The NDC leader got 50.70 percent of the vote against Akufo-Addo's 47.74 percent.
Akufo Addo, his running mate Mamoudu Bawumia and Jake Obetsebi Lamptey, the NPP chairman want the court to set aside the results arguing that the December 7 and 8 polls were marred by many irregularities.
They say 1,340,018 of the votes were not properly accounted for.