Nigeria’s opposition African Democratic Congress (ADC) is preparing to challenge a court ruling that invalidated the nomination of former Vice-President Atiku Abubakar as its presidential candidate ahead of the January 16 election.

The Federal High Court in Abuja also nullified the party’s current leadership, raising uncertainty over its ability to field candidates in the upcoming general election.

The ruling was delivered on Thursday by Justice Peter Lifu following a dispute over who has the lawful authority to lead the ADC.

The case was filed by Nafiu Bala Gombe, a former national deputy chairman of the party, who challenged the appointment of former Senate President David Mark as interim national chairman.

Gombe argued that Mark and other officials had not been elected at a national convention and that he should have taken over the party’s leadership following the resignation of its former chairman in 2025.

The dispute dates back to a period when several prominent politicians joined the ADC after disagreements within the Peoples Democratic Party (PDP). Among them were Abubakar, who served as Nigeria’s vice-president from 1999 to 2007, and Mark, who later assumed the party’s interim leadership.

However, the latest decision has reopened questions about the legality of the party’s leadership and its preparations for the presidential election.

In a statement, the ADC described the judgment as an attempt to weaken the opposition and frustrate Abubakar’s presidential ambitions. The party said it would appeal the decision at the Court of Appeal.

Abubakar, 79, also criticised the ruling, questioning why the leadership dispute had returned to court after an earlier judgment.

In July, another Federal High Court judge, Musa Liman, had ruled that Mark’s appointment was consistent with Nigerian law and the party’s constitution.

Reacting to Thursday’s decision, Abubakar said its timing was significant, coming a day after supporters turned out in large numbers to welcome him during a campaign event in Sokoto State.

He urged his supporters to remain focused and peaceful as the party pursues its appeal, insisting that Nigerians needed relief from the rising cost of living.

Despite the ruling, the Independent National Electoral Commission (INEC) has already published its final list of presidential candidates, which includes Abubakar as the ADC flagbearer. Former Rivers State Governor Rotimi Amaechi is listed as his running mate.

The legal dispute could therefore affect not only the presidential ticket but also hundreds of ADC candidates seeking elective positions.

The development has also drawn criticism from Peter Obi, who is contesting the presidency under the Nigeria Democratic Congress (NDC).

Obi, 65, said he was shocked by the judgment and warned against decisions that could create uncertainty ahead of an election.

He argued that political parties should be allowed to operate and compete freely, adding that the strength of Nigeria’s democracy depended on protecting opposition politics.

Obi had briefly joined the ADC before leaving for the NDC earlier this year, partly because of the legal disputes surrounding the party.

For now, the ADC’s appeal will be central to determining the effect of the latest ruling on its leadership and candidates. Abubakar, who is making his seventh attempt to become Nigeria’s president, has urged supporters not to lose focus as the legal process continues.