Five lawmakers of Chandrababu Naidu's Telugu Desam Party this evening met Vice President Venkaiah Naidu, who is also the chairman of the Rajya Sabha, to challenge four of their colleagues switching over to the BJP. The TDP delegation - two Rajya Sabha and three Lok Sabha lawmakers - have asked for the initiation of disqualification proceedings under the Tenth Schedule of the Constitution against the TDP lawmakers who merged with the BJP yesterday.

Four of TDP's six Rajya Sabha lawmakers - YS Chowdary, CM Ramesh, Garikapoati Mohan Rao, TG Venkatesh - met Venkaiah Naidu yesterday and gave him a letter that said they have "decided to merge" the TDP's Legislature Party with the BJP with immediate effect "under Paragraph 4 of the Tenth Schedule to the Constitution of India".

The fourth paragraph of the Tenth Schedule of the Constitution lists circumstances under which lawmakers who join other parties cannot be disqualified from the House. "The merger of the original political party of a member of a House shall be deemed to have taken place if, and only if, not less than two-thirds of the members of the legislature party concerned have agreed to such merger," the provision says.

The switchover was led by YS Chowdary, who was named TDP leader in Rajya Sabha just a few days ago. Considered close to Chandrababu Naidu, was a minister of state in the first Narendra Modi-led NDA government till March last year when TDP pulled out of the coalition.

Mr Chowdary said Andhra Pradesh's development could only be achieved by cooperation and not confrontation, in an apparent dig at the TDP chief who had quit the NDA over the centre's refusal to provide Special Status to Andhra Pradesh; he later became one of the key interlocutors of the opposition.

Incidentally, Income Tax department had raided residential and official premises of Mr Chowdary and Mr Ramesh last year over allegations of tax evasion and money laundering. Both had then claimed innocence.

Chandrababu Naidu, who is currently in Europe with family, yesterday tried to downplay his MPs switching to the BJP and said the TDP "will be back" and crises were nothing new to it.