The lawmaker announced the defection to hundreds of supporters in Akwa Ibom, as long expected.
The former Akwa Ibom State governor announced his defection to hundreds of supporters at a rally held in his honour in Ikot Ikpene.
He said, "Why APC? You need to know that I'm a nationalist. In troubled times like this, when a country is at war, all hands must be on deck to service the federation. This is a difficult moment for Nigeria.
"In a period of election or in a period of national emergency, everybody should put hands together to support the government to bring peace to people. I will like to be a conspirator who joins hands to conspire to bring food to the table of Nigerians."
The lawmaker's defection has long been expected since he met with President Muhammadu Buhari, Vice President Yemi Osinbajo, and APC national leader, Bola Tinubu, within the past six days.
Tinubu, APC chairman, Adams Oshiomhole, and Minister of Information and Culture, Lai Mohammed, were some of the top officials who graced the rally on Wednesday.
Senate Majority Leader, Ahmed Lawan (Yobe North) was also present at the rally with over a dozen senators of the APC to support Akpabio whose defection follows on the heels of the mass exodus of APC lawmakers, including Senate President, Bukola Saraki, who dumped the party for the PDP.
While speaking at the rally on Wednesday, Lawan said Akpabio's defection will shake the PDP to its very foundations.
He said, "Last two weeks, some of our colleagues have decamped to PDP and ADC, this has not shaken the party or the country. Today, the declaration by the one and only uncommon senator in the history of Nigeria has shaken Akwa Ibom and Nigeria to its very foundations.
"This defection has swallowed all previous defections. One that is equal to more than 14. This is one defection that has shaken the PDP to its very foundations."
In a letter, dated August 4, 2018, ahead of his defection, Akpabio resigned as the Senate Minority Leader of the 8th Senate and thanked the PDP for giving him the opportunity to lead the party's caucus for the past three years.