91st Constitutional Amendment Act, 2003

The 91st Amendment made two major changes:

Change 1 — Cap on Council of Ministers Size: The total number of Ministers (including the Prime Minister) in the Union Council of Ministers shall not exceed 15% of the total strength of the Lok Sabha (543 seats × 15% ≈ 81 ministers maximum).

Similarly, state cabinet size cannot exceed 15% of state assembly strength (minimum 12 ministers).

This was introduced because coalition governments were creating oversized cabinets to accommodate allies — leading to inefficiency and corruption.

Change 2 — Strengthening Anti-Defection Law: The original 10th Schedule (Anti-Defection Law, 1985) allowed a party split if at least 1/3rd of members defected together — this loophole was widely misused.

The 91st Amendment deleted the split provision entirely — now ANY defection (even a group) counts as defection and attracts disqualification.

The Anti-Defection Law (10th Schedule, 1985) disqualifies a member of Parliament/State Legislature if they:

1. Voluntarily give up their party membership
2. Vote against their party's direction in the House (vote against whip) without prior permission
3. Abstain from voting against party direction

The decision on disqualification is made by the Speaker of Lok Sabha / Chairman of Rajya Sabha.

While splits are banned, mergers are still allowed under the 10th Schedule: A group of at least 2/3rd of the party's members can merge with another party without attracting disqualification — but they must merge, not just join as a new faction.