LAGOS, Nigeria — A Nigerian court disqualified a leading presidential candidate Thursday, complicating the electoral process two months before the election.

A Federal High Court judge in Abuja, the country’s capital, ruled that the leadership of the African Democratic Congress, one of the three major parties contesting the January 2027 election, was illegally constituted and therefore voided the candidacy of Atiku Abubakar.

Earlier in the year, a court ordered the party deregistered for failing to meet constitutional requirements, but an appeals court overturned the ruling. The party and government critics say the case was orchestrated by the ruling party.

Nigeria is set to go to the polls next year against the backdrop of a troubled economy and escalating insecurity. Incumbent President Bola Tinubu faces a splintered opposition, mainly from Abubakar and Peter Obi, setting up a rematch of the 2023 presidential election.

Abubakar and Obi came second and third in 2023, respectively.

The campaign has gotten off to a slow start since August, as opposition parties remain mired in legal battles, boosting Tinubu’s chances at the polls.

“The timing of this ruling is no coincidence,” Abubakar said Thursday in a statement. “It is part of a strategy to weaken my support in the north and frustrate a campaign whose message is resonating across the country.”

The party said it would be appealing the judgment.