The 39-year-old lawyer had previously, in December 2018, announced her decision to file a suit to compel the 76-year-old president to undergo a medical examination to prove his fitness for the race.

According to the suit, marked FHC/ABJ/CS/112/2019, Atuejide brought four summons before the court pursuant to Sections 137(C) and 251(1) of the constitution.

She argued that a presidential candidate who has publicly displayed signs of unsound mind, such as the inability to think or act independently, loss of memory, dementia, and incoherence should be declared unfit to contest.

She said Buhari's display of some of these conditions, including disorientation, inability to understand clear language and questions, jumbled speech and mental decline, are medical signs that point to the president's unsoundness of mind that should lead to his disqualification.

The summon also asked that the president be subjected to a medical examination conducted by a team of independent medical experts constituted by the court. She said the result of the examination should be made public after which Buhari should be disqualified if he fails.

With the Independent National Electoral Commission (INEC) also joined alongside Buhari as a defendant in the suit, Atuejide prayed to the court to restrain the commission from recognising the president as a candidate for the February 16 election.

The court has ordered that a summon be served on both Buhari and INEC who have been asked to appear before the court for the determination of the suit. The NIP and the Action Peoples Party (APP) were also listed as plaintiffs.

Atuejide had said in December that the president's well-publicised health troubles have made it clear that the responsibilities of the office are well beyond his physical and mental capabilities at his old age.

"President Buhari is both physically and mentally unable to run the affairs of this country beyond 2019. It is my right as a concerned Nigerian, and as an interested party being myself a candidate at the forth coming Presidential elections to raise this alarm, and to take steps to stop this disaster from happening," she said.

She disclosed that her investigations have revealed that President Buhari is "indeed extremely forgetful, very absent minded, and suffers regular delusional attacks".

She pointed to the president's numerous public gaffes, administrative indecision, rare public appearances and several medical trips abroad to drive home her point.

Much has been made about Buhari's physical and mental capacities, especially in recent weeks when he's made embarrassing mistakes on his campaign trail.

He's misplaced certain dates of past events and slipped twice in two different states.

The health concerns have been largely fueled by the president's constant medical trips during his first term, including his controversial extended stays in London treating an undisclosed illness in 2017.

2019 presidential race

Despite the concerns over his health, the president is still a favourite to win the election. Atiku Abubakar of the Peoples Democratic Party (PDP) is his biggest candidate in an election involving 70 other candidates.

Alongside Atuejide in the chasing pack is Donald Duke of the Social Democratic Party (SDP), Kingsley Moghalu of the Young Progressive Party (YPP), Fela Durotoye of the Alliance for New Nigeria (ANN), and Omoyele Sowore of the African Action Congress (AAC).

Others are Tope Fasua of the Abundance Nigeria Renewal Party (ANRP), Adesina Fagbenro-Byron of the Kowa Party (KP), Chike Ukaegbu of the Advanced Allied Party (AAP), Hamza Al-Mustapha of the People's Party of Nigeria (PPN), Obadiah Mailafia of the African Democratic Congress (ADC), and many more.