Three of the lawmakers met Vice-President Venkaiah Naidu and submitted their resignations

Highlights 4 lawmakers of Chandrababu Naidu's TDP today joined the BJP

The TDP lawmakers of Rajya Sabha said they "decided to merge" with BJP

Chandrababu Naidu said the crisis was not new

Four of the six parliamentarians in Chandrababu Naidu's Telugu Desam Party today joined the BJP. This evening, the Rajya Sabha members met Vice-President Venkaiah Naidu, who is also the chairman of the upper house, and gave him a letter that said they have "decided to merge" the TDP's Legislature Party with the BJP with immediate effect. The lawmakers -- YS Chowdary, CM Ramesh, Garikapoati Mohan Rao, TG Venkatesh -- were accompanied by the new BJP working president JP Nadda.

Party chief N Chandrababu Naidu, who is currently vacationing with his family in Europe, said the crisis was not new and his workers have nothing to be nervous about, but he "condemned the BJP's attempts to weaken the TDP".

"We fought with the BJP only for Special Category Status and the state's interests. We sacrificed Central Ministers for Special Status," news agency ANI quoted him as saying.

The move will add to the BJP's strength in the Rajya Sabha -- where the NDA has only 102 members in the 245-seat house. It would also give the BJP a toehold in another southern state besides Karnataka.

Mr Nadda later told the media that the BJP believes in inclusiveness and "will be strengthened with their inclusion". "We will increase the base of the BJP in Andhra," he added.

In a resolution submitted to Venkaiah Naidu, the lawmakers said they have decided to "merge the Legislature Party of the TDP with the Bharatiya Janata Party (BJP) with immediate effect under Paragraph 4 of the Tenth Schedule to the Constitution of India". They also requested the chairman to allow the merger and treat them as members of the BJP Legislature Party.

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.

Earlier today, two of the lawmakers had announced their intention.

"Yes I am leaving the TDP. I will join the BJP," Telugu Desam Party's TG Venkatesh was quoted as saying by news agency ANI. "I have been a former member of ABVP and the BJYM (the BJP youth wing)," he added. ABVP is the student wing associated with the BJP's ideological mentor Rashtriya Swayamsevak Sangh. The TDP's senior leader YS Chowdary also admitted that he was switching camp.

Chandrababu Naidu quit the NDA last year over the Centre's refusal to provide Special Status to Andhra Pradesh and became one of the key interlocutors of the opposition. But his plan failed spectacularly. Arch-rival Jaganmohan Reddy, the chief of the YSR Congress, not only won the state elections, but also scooped up 22 of the state's 25 Lok Sabha seats.