The 91st Constitutional Amendment Act, 2003, is a significant legislative provision that primarily aimed to strengthen the Anti-Defection Law and impose a limit on the size of the Council of Ministers at both the Union and State levels. It was enacted in 2003 to solve the twin problems of political instability caused by frequent defections and the formation of excessively large "jumbo" cabinets used to reward defectors.
The amendment works by introducing key changes to the Constitution of India. It inserted Article 75(1A) for the Union and Article 164(1A) for the States, mandating that the total number of ministers, including the Prime Minister or Chief Minister, shall not exceed 15% of the total strength of the Lok Sabha or the respective State Legislative Assembly. For smaller states, Article 164(1A) also stipulated a minimum of 12 ministers.
Crucially, the Act strengthened the Tenth Schedule of the Constitution, which deals with the Anti-Defection Law, by removing the loophole that allowed a split in a political party if at least one-third of its legislators broke away. This provision, which was part of the original 52nd Constitutional Amendment Act, 1985, was frequently misused to engineer mass defections. The only exception that stayed the same was the provision for a merger, which requires the support of at least two-thirds of the legislators.
Furthermore, the amendment introduced Article 75(1B) and Article 164(1B), which disqualify a legislator who is a defector under the Tenth Schedule from being appointed as a minister until they are re-elected. It also added Article 361B, which bars a disqualified defector from holding any remunerative political post for the duration of their disqualification. The Act connects directly to the Tenth Schedule and the 52nd Amendment Act, 1985, by amending and strengthening the anti-defection framework established by the earlier law.