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.