National leader of the All Progressives Congress (APC),
Tinubu's assertion was in reaction to the statement by Governor Rochas Okorocha of Imo state, that 34 governors have already endorsed Buhari for a second term.
The APC stated this in Akure, Ondo State, on Wednesday, November 22, 2017.
He said "governors cannot appropriate the power of endorsement to themselves."
He added that the party's flagbearer in the 2019 presidential election will emerge through a democratic process.
He said, "Buhari is a believer in the process. He believes in the rule of law. We wanted him even before the last convention and primary of the party."
"We followed all the constitutional provision and an individual or group’s opinion does not really matter at this stage, Buhari will want a normal process.
"Buhari that, I know, who says he will lose at any convention? But if the national body, the national executive committee and all of us as members endorsed him as our single candidate, we will not be violating INEC regulations, we will not be violating our party constitution.
"What you are hearing is just a campaign by other people who might like to do so."
Although Buhari has not disclosed his intention about 2019, his supporters have been agitating for his re-electon.