An amendment, when proposed by absolute majority in both House of Representatives and Senate, is ratified by popular vote, but there must be a favourable majority not only in the Commonwealth but in a majority of the States too.
In Canada, Parliament and Provincial legislatures, both participate in the amending process. The method of amending the Indian Constitution is not so complicated, for it avoids the difficult process laid down by the American and Australian Constitutions. Some parts of the Constitution can be amended by a simple majority in both.
Houses of Parliament; certain specified subjects require a majority of the total membership in each House of Parliament, a majority of not less than two-thirds of the members present and voting in each House, and ratification by one-half of the States; the remaining provisions of the Constitution require a majority of the total membership in each House of Parliament and a majority of not less than two-thirds of the members present and voting in each House.
But the degree of rigidity depends upon two other factors beyond the language of the amendment. When the legislature is the judge of its own powers under the constitution, there is no legal barrier to its encroachments.
When the courts determine the constitutionality or otherwise of the acts of the legislature, they prevent legislative usurpation.
Undoubtedly, judges respond to changing circumstances and public opinion, but they do so rather more slowly than the legislature. Secondly, it depends upon the content of the constitution.
Some constitutions are short, others long; some limited to general provisions, others replete with details; some willing to leave civil liberty with the legislature, others the reverse.
“What makes the Indian Constitution so rigid,” says Jennings, “is that in addition to somewhat complicated process of amendment it is so detailed and covers so vast a field of law that the problem of constitutional validity must often arise.”