Al-Mustapha was declared the winner of the presidential ticket of the People's Party of Nigeria (PPN) on Sunday, October 7, 2018.

He won 3,564,262 votes to emerge victorious over his opponents, Dr Imuetinyan Igbinnosa (2,183,856 votes) and Chief Isiaka Olorunnimbe (1,400,755 votes) at the party's presidential primary election conducted at its 2018 National Convention held in Ado Ekiti, Ekiti State.

He was declared winner by the Chairman of the Presidential Primary Elections Committee and Ekiti PPN Chairman, Dare Adekolu, who called for support for the party that is committed to saving Nigeria from poverty, unemployment and underdevelopment.

Through his representative, Zakaria Husseini, Al-Mustapha, who was absent from the convention promised to save Nigeria and make the country prosperous with quality leadership.

Al-Mustapha had been arrested and tried for the murder of Kudirat Abiola but was discharged and acquitted in 2013 for lack of enough incriminating evidence.