These aspirants include former Vice President, Atiku Abubakar, Senator from Kano, Rabiu Kwankwaso, Sokoto State Governor, Aminu Tambuwal, former Kaduna State Governor, Ahmed Makarfi, the Senate President, Bukola Saraki among others.
They also pledged to support whoever emerged as the party's flagbearer.
Abubaker defected again in May to PDP where he on Sunday clinched the ticket to tackle incumbent President Buhari in the 2019 presidential election.
Concise News had reported earlier that the former Vice President emerged victor of the party's presidential primary with 1,532 votes while his closest contender, Aminu Tambuwal, polled 693 votes.
"My commendation also goes to the government and people of Rivers State for providing the best necessary facilities for hosting over 5000 delegates, campaign workers, security personnel, observers, media people and others who came to play one role or the other in the convention".
He said all the aspirants are eminently qualified to lead the country and urged the delegates to elect a person who will bring Nigeria together.
Senate confirms Brett Kavanaugh to Supreme Court amid protests
In a twist, Murkowski said she will state her opposition but vote "present" as a courtesy to Kavanaugh supporter Sen. The allegations against Kavanaugh elicited conversations about the #MeToo movement that could reach into the future.
Chairman of convention planning committee Ifeanyi Okowa, who is governor of the southern Delta state, said all 12 contenders were still in the running.
Saraki made this known in a series of tweets on Sunday, after Atiku was announced as victor of the PDP presidential primaries.
Former governor Obi described the victory of Atiku as a consummation of the wishes and desires of most Nigerians, both high and low.
Jonathan spoke at the convention of the PDP in Port Harcourt in the early hours of Sunday.
"All Progressives Congress being a party whose cardinal principle is change and headed by a comrade/activist whose main concern is for the common man, yet, such impunity could take place under its watch". It also shows that our citizens, irrespective of their individual and group interests, are capable of holding peaceful and credible elections that meet global standards.