The Anti-Defection Law is a constitutional provision contained in the Tenth Schedule of the Indian Constitution. It was introduced by the Constitution (Fifty-second Amendment) Act, 1985, to curb the problem of rampant political defections, which had caused governmental instability, a phenomenon popularly known as "Aaya Ram, Gaya Ram". The law aims to ensure stability and strengthen party discipline by penalizing legislators who switch parties.
The mechanism for disqualification applies to Members of Parliament (MPs) and Members of State Legislative Assemblies (MLAs). A legislator can be disqualified if they voluntarily give up membership of their political party, or if they vote or abstain from voting contrary to any direction (whip) issued by the party, unless the party condones the action within 15 days. The authority to decide on a member's disqualification rests with the Speaker or Chairman of the respective House.
The law connects to Article 102(2) and Article 191(2) of the Constitution, which deal with disqualification of members of Parliament and State Legislatures, respectively. A significant judicial interpretation came in Kihoto Hollohan v. Zachillhu (1992), where the Supreme Court upheld the law's validity but ruled that the Presiding Officer's decision is subject to judicial review.
The law was substantially amended by the Constitution (Ninety-first Amendment) Act, 2003. This amendment deleted the provision in the Tenth Schedule that protected legislators from disqualification in case of a party split by one-third of its members. The exception for a merger remains, provided at least two-thirds of the members of the legislative party agree to merge with another party. The 2003 amendment also added that a disqualified member is barred from holding any remunerative political post until their term expires.