While all eyes are on the east, where a crisis is underway in Mamata Banerjee-led Trinamool Congress (TMC) in West Bengal, a possible rift is silently brewing on the Western front too, where a key opposition party is heading towards a second split.Shiv Sena (UBT) leaders have asserted that all the Lok Sabha MPs of the party are with Uddhav Thackeray. (Raju Shinde/HT Archives)Bengal dominated headlines the past week, where a majority of TMC Lok Sabha MPs, led by Kakoli Ghosh Dastidar, parted ways with Mamata Banerjee.However, while the Opposition INDIA bloc was reeling with a major setback in Bengal, several of Eknath Shinde's Shiv Sena leaders had already made attempts so that rival Uddhav faction leaders switch their sides.Thackeray-led Shiv Sena has, meanwhile, has amped up efforts to reach out to its party MPs over possible defections. Shiv Sena (UBT) has rubbished defection rumours, with Uddhav Thackeray calling a meeting of all nine of its members in the Lok Sabha on Sunday.Also Read: As poaching buzz returns, Uddhav summons Sena (UBT) MPs to Mumbai“Four MPs were physically present, while five joined online,” Shiv Sena (UBT) Rajya Sabha MP Sanjay Raut told reporters after the meeting at Thackeray’s residence, Matoshree.Arvind Sawant, Anil Desai, Rajabhau Waze and Sanjay Patil attended the meeting in person, and Omprakash Raje Nimbalkar, Bhausaheb Wakchaure, Nagesh Bapurao Patil Ashtikar and Sanjay Deshmukh attended it online.Meetings and invitations fuel rumoursShiv Sena (UBT) MP Sanjay Deshmukh on Monday met Union minister Prataprao Jadhav, who belongs to the Shinde-led Shiv Sena.The meeting came days after Union minister Pratap Jadhav of the Shiv Sena said it was only a matter of time before Shiv Sena (UBT) MPs switched sides.The Shiv Sena minister hinted at an “Operation Tiger", launched by Uddhav's rival-Eknath Shinde, to bolster party's numbers in the Parliament and within the BJP-led National Democratic Alliance (NDA).However, in all this controversy, the number 6 plays the major role. The Shiv Sena (UBT) has 9 MPs in the Lok Sabha.So, the rival Sena camp requires at least two-thirds or six MPs to switch sides to formally engineer a split in the parliamentary party and escape disqualification under the anti-defection law.Also Read: Ex-AIADMK minister Vijayabaskar resigns as MLAThe defection in Bengal was seen as BJP's attempts to bolster its numbers in the Parliament as the party doesn't have a majority of its own in the Lok Sabha. The increasing numbers will help party's prospects to get key legislations passed in the Parliament, which have been stalled or rejected due to the inadequate numbers.Shiv Sena says 'Our doors are open'Days after Union minister Pratap Jadhav dropped hits at Shiv Sena (UBT) MPs switching sides, another Sena leader, Pratap Sarnaik, said his party's doors were open to anyone who believed in Eknath Shinde's leadership.Sarnaik, a minister in Maharashtra, on Tuesdsay said anyone who believed in the ideals of Sena founder Bal Thackeray and leadership of deputy CM Shinde was welcome, PTI reported.Also Read: TMC’s Abhishek Banerjee grilled for 6 hours by CID in ‘provocative speech' case"If public representatives like MPs and MLAs do not trust their leadership, and if they are willing to trust the leadership of Eknath Shinde, then the doors of the Shiv Sena are open to them," he said, adding, "We will give them priority if they thought of it (anytime) in the future."However, Shiv Sena (UBT) leaders have asserted that all the party MPs are with Uddhav Thackeray.This comes even as several lawmakers from the Shiv Sena (UBT) camp have met top leaders of the Shiv Sena and the BJP in recent weeks.While Hingoli MP Nagesh Bapurao Patil Ashtikar recently met Eknath Shinde, Nashik MP Waje met Shinde's son. Earlier this year, Ashtikar and Sanjay Deshmukh had attended a dinner party thrown by Shiv Sena leader and union minister Pratap Jadhav, giving rise to speculation about a rift within the Sena (UBT).