The 'basic structure' doctrine, under which Parliament cannot amend the Constitution so as to destroy or alter its basic structure even while exercising its power under Article 368, was propounded by the Supreme Court in:

In Kesavananda Bharati v State of Kerala (1973), a thirteen-judge Bench of the Supreme Court held, by a seven-to-six majority, that the power of Parliament to amend the Constitution under Article 368, though plenary, does not extend to altering or destroying the basic structure or framework of the Constitution, whose features include the supremacy of the Constitution, the rule of law, judicial review, secularism, democracy and the federal character of the polity. Golak Nath (1967) had earlier held that fundamental rights were unamendable, a position substantially modified by the basic structure doctrine; Minerva Mills (1980) and S R Bommai (1994) applied and extended the doctrine rather than propounding it; and A K Gopalan (1950) concerned preventive detention and 'procedure established by law'. Kesavananda Bharati is therefore the correct answer.