The lawmakers gave their reason while addressing journalists on Thursday in Abuja after announcing their defection on the floor of the house.
Obi, who represents Ideato-North/Ideato-South of Imo, said that he was a member of the APC before joining AA to contest the 2019 election.
He said he had been representing his constituents very well on the platform of the AA but had to defect due to crisis in the party.
”I have been representing my people until now that I took the decision after due consultation with my constituents; that is the people of Ideato-North/Ideato-South.
“We decided that I defect to the APC because of the very persistent crisis and rivalry in the AA.
“A lot of litigation and factions created. So, I had no other option than to take this decision, the decision I have consummated today on the floor of the house.
“So, I am now a member of the APC and no more AA,” he said.
On his part, Chima said that though he ran election under the platform of AA, he collaborated with the APC to win the contest.
According to him, after the election, we discovered that AA had engrossed itself with a lot litigation and leadership crisis.
Meanwhile, the National Organising Secretary of the APC, Mr Emmanuel Ibediro, has congratulated the lawmakers for returning to the party.
He described the defection as “harvest of goodwill” that the party had created not just in Imo but in Nigeria.
“Joining our party today is an endorsement of the good things the party is doing; the good things the president is doing and it shows the tacit support for the politics of the APC.
“I’m happy today that our party has been made richer by the entrance of these two powerful honourable members from my state,” he said.