Mr Doherty said in a statement on Saturday that he resigned from the party some days ago.
According to him, the convention will proceed.
The two-day event has as its theme, “Unity in Progress: Consolidating the Renewed Hope Agenda.”
The event will take place on Saturday at the Eagle Square, Abuja.
Correspondents covering the convention noticed a heavy presence of party stalwarts, members, and supporters in their colourful party outfits.
Mr Kalu gave the charge in Abuja on Friday while hosting a delegation of the support group from Edo, Ekiti and Katsina.
The award was presented at a ceremony held in Abuja on Thursday.
Unease lies at the head of President Bola Tinubu as widespread terrorist attacks and violent kidnappings by bandits and other criminals run Nigeria ragged.
Mr Abubakar, 79, is expected to throw the kitchen sink at his 2027 presidential ambition, which may potentially be his last shot to become Nigeria’s president.
APC’s National Convention Coordination Committee Secretariat has declared its readiness to ensure a transparent and credible process ahead of its convention.
