In a severe blow to YSR Congress Party, two of its MPs on Sunday backed rival TDP which is slated to form the government in residual Andhra Pradesh.

While three-time Nandyal MP SPY Reddy joined TDP, his colleague Butta Renuka from Kurnool constituency claimed that she has not joined TDP but will extend issue-based support to N Chandrababu Naidu-led party.

"I have joined TDP because BJP is ruling at the Centre and TDP is the ruling party in Seemandhra. I could better serve my constituency if I am with TDP," Reddy told PTI.

He claimed that he had not communicated to YSR Congress about his sudden decision to join TDP.

He also dismissed allegation that he defected to TDP because of his strained relationship with YSR supremo, saying there was no difference of opinion between them.

Briefing reporters after meeting Naidu, Renuka said she called on the TDP supremo for the development of her constituency.

"Today I have actually come to meet Chandrababu Naidu. My constituency needs his support for development...He (Naidu) accepted and agreed that he will give his support to my constituency," she told reporters.

Interestingly, both the YSRCP MPs called on Naidu separately. Renuka further clarified that she has not joined TDP.

"I have not joined the party (TDP)" she said. Asked whether she will be functioning as YSRCP member or a TDP parliamentarian, Renuka stated that she would extending issue based support.

With this, TDP, which has 16 Lok Sabha MPS, has got the support of two more MPs. Before Reddy's decision to part ways, YSR Congress had nine MPs in Lok Sabha.

YSR Congress sources said Reddy by joining TDP attracts the anti-defection law.

Lok Sabha officials said under Schedule 10 of the Anti-Defection law, Reddy can attract disqualification for which the party will have to move a petition to the Speaker for such action.

One of the grounds for defection is when a member voluntarily gives up membership of his party.