The tribunal sacked Mr Sule with a split decision.
The governorship election petition tribunal sitting in Lafia, Nasarawa State, has sacked Governor Abdullahi Sule of Nasarawa State and declared David Ombugadu, the candidate of the opposition Peoples Democratic Party (PDP), as the duly elected governor.
In a split judgement delivered by the three-member tribunal on Monday, two of the judges agreed that the election was won by the PDP while the other dissented.
Governor Sule of the All Progressives Congress (APC) sought re-election for a second term but faced stiff opposition during the election.
Mr Sule polled a total of 347,209 votes to defeat his closest opponent, Mr Ombugadu, who secured 283,016 votes.
In the lead judgment delivered virtually, lasting more than four hours on Monday, the chairperson of the three-member tribunal, Ezekiel Ajayi, declared Mr Ombugadu the rightful winner of the election.
Chiemelie Onaga, a member of the panel, agreed with the judgement read by the panel chairperson.
Mr Ajayi declared that Mr Ombugadu provided the results of the various polling units and forms EC 8A and proved to the tribunal that the results were manipulated in favour of the APC.
He said that based on the proof from the various polling units before the tribunal, Mr Ombugadu had the majority of valid votes at the election.
He ordered INEC to withdraw the certificate of return issued to Mr Sule and issue a new one to Mr Ombugadu.
The dissenting judgment was delivered by Ibrahim Mashi, who dismissed the petition filed by the PDP candidate for lacking in merit.
He said the petitioner failed to prove his case and upheld INEC's declaration of Mr Sule as the winner.
Reacting to the tribunal's decision, Mr Ombugadu's counsel, Johnson Usman, a Senior Advocate of Nigeria (SAN), lauded it for a detailed judgment.
The counsel said the tribunal had proved that the court is the last hope of the common man by affirming the decision of the majority of the people of the state at the poll.
Mr Sule has also vowed to appeal the tribunal's decision.