LAGOS, Nigeria

A Nigerian election petition tribunal on Friday declared opposition People's Democratic Party (PDP) winner of a Sept. 22 governorship ballot in southwest Osun state.  

The decision sets aside an earlier result by the electoral body.  

The three-man tribunal said in a two-to-one split decision that PDP's Ademola Adeleke won the ballot by a small margin and should have been declared the governor-elect.

The tribunal said a supplementary ballot of Sept. 27, which was called after the electoral body canceled votes in certain areas and declared the election inconclusive, was unlawful as there held no basis.

The electoral body declared Gboyega Oyetola of the ruling All Progressives Congress winner in the election after he polled the highest votes following the supplementary poll. 

But the tribunal canceled the votes from the supplementary election and declared PDP's Adeleke winner -- a ruling which, if confirmed by the higher courts, may well affect several governorship ballots held March 9.  

The tribunal also cancelled results from 17 polling units on the grounds of substantial non-compliance with the law.  

But the minority ruling of the tribunal upheld the election outcome and said the electoral body was right to have declared the poll inconclusive in line with its internal rules.  

The electoral body recently had been declaring elections inconclusive if the margin between the two leading contestants is less than the number of canceled votes -- a practice some lawyers insist was at variance with the electoral law. 

The body's decision to call a supplementary ballot followed the cancelation of votes across seven polling units in the state. But the tribunal said the cancelation of such votes -- after it had initially been announced by the same body -- is unlawful and had robbed Adeleke his victory.  

The tribunal ruling is subject to appeal up to the Supreme Court.  

Oyetola had since been sworn in as governor. He will likely keep his seat until the top court upholds the ruling of the tribunal.