Adeleke was the candidate of the Peoples Democratic Party (PDP) in the 2018 Osun State governorship election, an election he lost to Gboyega Oyetola of the All Progressives Congress (APC).

Adeleke and the PDP had filed an appeal before the Supreme Court after they lost to Oyetola and the APC in the Court of Appeal in May.

The Court of Appeal had upheld Oyetola's victory after an election tribunal initially ruled, in March, that Adeleke won the election.

In its ruling early on Friday, a majority of five judges in the seven-member panel of the Supreme Court affirmed Oyetola as the winner of the election based on a technicality in the tribunal ruling.

Atiku promptly released a statement to assure Adeleke that the love, acceptance and endorsement that the people of Osun bestowed on both him and the PDP is not over and cannot be overlooked.

He said the ruling is not the end of the road for the former senator, and that he'll continue to be in the hearts and minds of the people.

He said, "Those who think this is the end of the road for Senator Adeleke and the Peoples Democratic Party in Osun, are greatly mistaken. This is not the end. Not even the beginning of the end. No. Today marks the continued ascendancy of Senator Adeleke and his party in the hearts and minds of his people.

"They had expected that the progress and development that the Adeleke family had consistently brought to Osun will be translated to their governance. That hope is not dead. Only delayed.

"I extend my right hand of brotherhood to Senator Adeleke in all his future endeavours and I assure the good people of the state of Osun that the Peoples Democratic Party remembers their love and acceptance and will never forget to stand by them no matter the situation."

Atiku also lost the 2019 presidential election to President Muhammadu Buhari of the APC, an election he has contested at a tribunal and is expected to end up at the Supreme Court.

In his Friday statement, he urged the judiciary to ensure that justice is done irrespective of undue pressure.

"Finally, I urge the nation's judiciary to take a pulse of the nation and reflect it. In their hands, God has placed a great responsibility. 

"The duty to ensure that justice is done, irrespective of the pressure to do otherwise, by the powers that be," he said.

Oyetola was declared the winner of the election after winning a supplementary election in September 2018.

Adeleke's initial victory was declared inconclusive because the victory margin of 353 votes over Oyetola was less than the 3498 votes cancelled in seven polling units, a situation that required a supplementary election.

After the supplementary election, the poll closed with Oyetola winning a total 255,505 votes, 482 more votes than Adeleke's 255,023.