S.P.Y. Reddy, who was elected from Nandyal on YSRCP ticket, joined the TDP in the presence of its leader N. Chandrababu Naidu in Delhi.
Neelakantham, husband of YSRCP MP from Kurnool Butta Renuka, also joined the TDP.
S.P.Y. Reddy told reporters that he joined the TDP for the development of his constituency. He claimed that he was elected from Nandyal on the basis of his popularity in the constituency.
S.P.Y. Reddy had quit the Congress and joined the YSRCP late last year after the Congress-led UPA government decided to carve out a Telangana state.
He was re-elected to Lok Sabha from Nandyal constituency in Kurnool district.
Renuka, who was elected from Kurnool constituency in the same district, is likely to join the TDP soon.
TDP leader C.M. Ramesh said Neelakantham joining the TDP amounted to Renuka switching loyalties. He claimed that many YSRCP legislators will join the TDP soon.
The YSRCP had bagged eight out of 25 Lok Sabha seats in Andhra Pradesh (Seemandhra). The TDP won 15 and its ally the BJP two seats.
TDP came to power in Andhra Pradesh by bagging 102 seats in 175 member assembly. YSRCP won 67 seats.