New Delhi, June 12 -- A third Rajya Sabha member of the crisis-hit Trinamool Congress (TMC) quit on Thursday, a day after Sushmita Dev resigned from the Upper House, amid the party's attempts to salvage the situation. The crisis, however, deepened on Thursday with Mamata's close aide Kalyan Banerjee issuing an ultimatum to the party chief to choose between her nephew Abhishek Banerjee and veterans like him, accusing the party national general secretary of "arrogance" and "fluctuating mindset". The TMC has been firefighting since it lost power in West Bengal last month after a 15-year rule. It expelled two of its 78 legislators in the state before 57 of them rebelled and backed Ritabrata Banerjee as leader of the opposition in the assembly. At least 16 TMC Lok Sabha members rebelled and met West Bengal chief minister Suvendu Adhikari. On Thursday, Prakash Chik Baraik became the third of TMC's 13 Rajya Sabha members to resign. Baraik submitted his resignation to Rajya Sabha chairman CP Radhakrishnan. On Monday, TMC's Sukhendu Sekhar Ray quit the Rajya Sabha. TMC Rajya Sabha floor leader Derek O'Brien said they tried to reach out to every lawmaker, including Baraik, fearing resignations. People aware of the matter said Baraik cited a family member's illness for his unavailability to the TMC leadership. There is little clarity on the names of TMC lawmakers who signed a letter to Lok Sabha Speaker Om Birla for a separate sitting area for their bloc. TMC general secretary Abhishek Banerjee met Congress leader Rahul Gandhi on Wednesday to explore possibilities to deepen ties in the second such meeting in two days. The TMC rejected speculation that the two parties were discussing a merger. On Tuesday, TMC chief Mamata Banerjee met Congress leader Sonia Gandhi. The TMC leadership is expected to meet Congress chief Mallikarjun Kharge. The TMC has not ruled out the possibility of an alliance with the Congress in West Bengal, something it has avoided since 2012. The TMC swept to power in 2011 in alliance with the Congress. Kalyan, also a senior advocate, declared he would remove himself from all legal matters and court petitions concerning Abhishek, although the MP said he would continue contesting cases related to the party. Kalyan, who resigned as the TMC chief whip in Lok Sabha in August last year and was recently reappointed to the post in the wake of the rebellion of 20 party MPs in the Lower House, has so far remained among the few still standing in support of the Mamata Banerjee-led party structure and has strongly criticised the rebel camp. The rift between the two leaders, however, came to a tipping point after Kalyan - who had been representing Abhishek in the Calcutta High Court in a signature forgery case of the CID - was allegedly informed that a separate writ petition was filed by the Diamond Harbour MP with regard to the search operations conducted by the agency at the TMC office at Mamata Banerjee's Kalighat residence and Abhishek's Camac Street office. "The two cases are connected, and I had mentioned the search operation issue before the bench that was hearing the signature forgery matter. The legal strategy was to seek leave in the forgery case, citing the illegal search operation. The judge had listed the matter to be heard on Thursday. Post midnight, some emissaries of Abhishek came to me to inform that a separate writ has been filed on the CID raid issue. I was taken aback since I had no knowledge of it," Kalyan told reporters....