New Delhi, June 19 -- Trinamool Congress (TMC) national general secretary Abhishek Banerjee arrived in the national capital on Friday, accompanied by party MP Derek O'Brien, to launch a high-stakes legal and political challenge against a faction of rebel MPs.

The delegation is scheduled to meet Lok Sabha Speaker Om Birla to address the announcement by 20 TMC MPs who have declared a merger with the Nationalist Citizens Party of India (NCPI).

This move follows a widening internal crisis for the TMC, which is currently grappling with a dual rebellion: 58 MLAs in West Bengal, led by expelled leader Ritabrata Banerjee, and the 20 Lok Sabha MPs led by Kakoli Ghosh Dastidar.

Meanwhile, senior party MP Saugata Roy has reiterated the party's fi...