Section 40A(7)(a) in The Howrah Municipal Corporation Act, 1980
(a)one or more Councillors who are the members of such recognised political party have -(i)voluntarily given up his or their membership of such recognised political party, or(iA)[ joined another recognised political party, or] [Sub-clause (iA) inserted by W.B. Act 6 of 2001.](ii)have exercised the voting right contrary to the manner of voting of the majority of the Councillors set up by such recognised political party in the Corporation, or