New Delhi, June 15 -- At least 20 rebel lawmakers of the Trinamool Congress (TMC) on Sunday told speaker Om Birla that they have merged with a little-known Tripura-based party, strengthening the National Democratic Alliance and setting the stage for one of the biggest defections in India's parliamentary history.

At least 20 lawmakers of the TMC met Birla on Sunday and submitted a letter that said the rebel group had merged with the Nationalist Citizens Party of India or NCPI, which was formed in 2022 and fought its last election in 2023.

The party currently doesn't have a lawmaker anywhere in the country. According to a Lok Sabha functionary, Birla will now verify the signatures of 20 MPs before approving the merger.

"We, 20 MPs, have ...