What is the Nationalist Citizens Party and why is it at the centre of the TMC rebellion?

A relatively unknown regional outfit from the Northeast has unexpectedly emerged as a key player in national politics. The Nationalist Citizens Party NCP, which until now had no representation in Parliament, has shot into the spotlight after 20 rebel MPs from the Trinamool Congress (TMC) announced plans to merge with it and extend support to the BJP-led National Democratic Alliance (NDA). The announcement was made by rebel TMC MP Kakoli Ghosh Dastidar after a meeting with Lok Sabha Speaker Om Birla on Sunday.