Senators Dino Melaye (Kogi West), Rabiu Kwankwaso (Kano central) and 13 others have formally defected from the All Progressives Congress (APC) to the opposition Peoples Democratic Party (PDP).
Their defection was announced in a letter read by Senate President Bukola Saraki on Tuesday.
The other defectors are Adesoji Akanbi (Oyo South), Monsurat Sunmonu (Oyo Central), Rafiu Ibrahim (Kwara South), Suleiman Hunkuyi (Kaduna North), and Lanre Tejuoso (Ogun Central).
Others are Usman Nafada (Gombe), Ibrahim Dambaba (Sokoto), Mohammed Shittu (Jigawa) Isa Misau (Bauchi) Suleiman Nazif (Bauchi) Shaaba Lafiagi (Kwara) and Barnabas Gemade (Benue).
Senator Abdul-Azeez Murtala-Nyako (Adamawa) who had earlier dumped the APC for the African Democratic Congress also formalised his defection.
Saraki, whose Abuja home was earlier barricaded by security forces, blamed the APC for the development.
The Senate president is expected to announce his defection from the APC soon.
