Tambuwal has his eyes on running for president in 2019 and is the preferred choice of PDP governors, according to party insiders.
Most members of the Sokoto state house of assembly are expected to move with him to his new party.
Tambuwal, who defected to APC when he was speaker of the house of representatives in 2013, does not need to resign his governorship to contest in the presidential primary of PDP.
They are Aminu Shehu Shagari, Kabiru Marafa Sokoto, Abdulsamad Dasuki and Bashir Salihu.
Also, Ibrahim Danbaba, one of the three senators, has left APC for PDP.
Tambuwal’s predecessor as governor, Aliyu Wamakko, now a senator, is also expected to return to PDP.