The INEC chair, Mahmood Yakubu, will appear to testify at the presidential election court on the subpoena in Atiku's case challenging Mr Tinubu's victory in the February election.
The chairman of the Independent National Electoral Commission (INEC), Mahmood Yakubu, will on Thursday testify before the Presidential Election Petition Court in Abuja.
Mr Yakubu will testify in Atiku Abubakar's petition challenging President Bola Tinubu's victory at the 25 February presidential election.
Atiku, the presidential candidate of the Peoples Democratic Party (PDP), accused INEC and Mr Tinubu of the All Progressives Congress (APC) of manipulating the polls.
His lead counsel, Chris Uche, on Tuesday, informed the five-member panel of the court chaired by Haruna Tsammani that Mr Yakubu would appear before it on Thursday.
At the behest of Atiku's legal team, Mr Yakubu had been subpoenaed to testify on the conduct of the disputed election.
Also, he is expected to tender some sensitive electoral documents in aid of the petitioner's suit.
Mr Uche, a Senior Advocate of Nigeria (SAN), put INEC, Mr Tinubu and APC's legal teams on notice concerning Mr Yakubu's scheduled appearance on Thursday to forestall any impediment that may obstruct the hearing.
Atiku calls first star witness
After calling 18 witnesses to testify for the petitioner, Mr Uche, on Tuesday, called his client's first star witness.
The witness, Alex Ter, a lawyer and former Attorney General of Benue State, in his testimony, alleged that the February presidential poll was fraught with widespread irregularities as it was conducted in disregard of the Electoral Act, 2022.
In his witness statement on oath, Mr Ter said he was the national coordinator Situation Room for the PDP during the February 25 presidential election in Abuja.
He presented three video clips featuring INEC chair Mr Yakubu and INEC's Commissioner for Voter Education, Festus Okoye, who both pledged that the electoral umpire would electronically transmit the election results.
The third video concerned the European Union Election Observer Mission, which was admitted as an exhibit by the court.
Also, the court admitted the guidelines for election officers 2022 and the manual for election guidelines 2023 as exhibits.
Sign up for free AllAfrica Newsletters
Get the latest in African news delivered straight to your inbox
Mr Ter also tendered screenshots of the INEC IReV portal.
Despite Mr Tinubu and APC's objections to the admissibility of the documents, the court admitted the videos played in court.
Last Saturday, similar video clips were tendered by Peter Obi's Labour Party, also contesting Mr Tinubu's victory.
Atiku and Mr Obi came second and third, respectively, in the race, but the pair are urging the court to declare each of them president.
They are also calling for a fresh poll.
While being cross-examination by INEC's lawyer, Abubakar Mahmoud, a SAN, Mr Ter said he was not at the National Collation Centre in Abuja, but was at the PDP situation room in Abuja.
The witness told the court that he was not an ICT expert. He clarified that his report on the election's outcome was obtained from agents of the PDP at the collation centres.
Mr Ter, Atiku's 19th witness, told the court under cross-examination by Mr Tinubu's lawyer, Akin Olujinmi, a SAN, that the presidential election was nullity owing to alleged electoral malpractices by INEC.
At the end of Mr Ter's testimony, the court adjourned the suit until Wednesday for further hearing.
