ABUJA, Oct 26 (Reuters) – Nigeria’s Supreme Court on Thursday upheld President Bola Tinubu’s election win, bringing to an end a legal challenge brought by his two main rivals, who argued that his victory was marred by irregularities.

The ruling will give the 71-year-old Tinubu a clear mandate to govern Africa’s most populous nation, which is grappling with double-digit inflation, foreign currency shortages, a weakening naira, widespread insecurity and crude oil theft.

Nigeria returned to democracy in 1999 after three decades of almost uninterrupted military rule, but accusations of ballot-rigging and fraud have followed its electoral cycles.

The judgment by seven Supreme Court judges, which is final, follows a pattern seen in previous presidential elections that have been challenged in court. None of the attempts to overturn results through the courts has been successful.

Atiku Abubakar of the People’s Democratic Party and Peter Obi of the Labour Party came second and third respectively in the February vote, but rejected the result and called for Tinubu’s win to be annulled.

The two opposition leaders had appealed a Sept. 6 tribunal judgment that endorsed Tinubu’s victory.

In the appeal, they argued that the electoral commission failed to electronically transmit results from polling stations to an online portal, which undermined their authenticity.

They also said Tinubu had won less than 25% of the vote in the federal capital Abuja so he did not meet the legal threshold to become president.

The judges dismissed all their arguments.

“There is no merit in this appeal, and it is hereby dismissed,” said Supreme Court judge John Okoro.

The court also rejected Atiku’s bid to introduce new evidence that alleged Tinubu had submitted a forged university certificate to the electoral agency. Tinubu had denied this.

(Reporting by Camillus Eboh and MacDonald Dzirutwe; Editing by Estelle Shirbon and Sharon Singleton)