CPI(M) expelled Chatterjee as he refused to quit as Speaker
Ten-time MP Somnath Chatterjee was expelled from the CPI(M) in 2008 after he refused to resign as Lok Sabha Speaker and vote against the UPA government in a no-confidence motion. The CPI(M) had then withdrawn its support from the UPA in opposition to the civil nuclear deal with the US. Chatterjee went on to complete his term as the Speaker.