The basic structure doctrine was further clarified in "Minerva Mills v. Union of India". The 42nd Amendment had been enacted by the government of Indira Gandhi in response to the Kesavananda Bharati judgment in an effort to reduce the power of the judicial review of constitutional amendments by the Supreme Court. In the Minerva Mills case, Nanabhoy Palkhivala successfully moved the Supreme Court to declare sections 4 and 55 of the 42nd Amendment as unconstitutional. The constitutionality of sections 4 and 55 of the 42nd Amendment were challenged in this case, when Charan Singh was caretaker Prime Minister. Section 4 of the 42nd Amendment, had amended Article 31C of the Constitution to accord precedence to the Directive Principles of State Policy articulated in Part IV of the Constitution over the Fundamental Rights of individuals articulated in Part III. Section 55 prevented any constitutional amendment from being "called in question in any Court on any ground". It also declared that there would be no limitation whatever on the constituent power of Parliament to amend by way of definition, variation or repeal the provisions of the Constitution. On 31 July 1980, when Indira Gandhi was back in power, the Supreme Court declared sections 4 & 55 of the 42nd amendment as unconstitutional. It further endorsed and evolved the basic structure doctrine of the Constitution. As had been previously held through the basic structure doctrine in the "Kesavananda" case, the Court ruled that Parliament could not by amending the constitution convert limited power into an unlimited power (as it had purported to do by the 42nd amendment).