The petitioners challenged the constitutional validity of the Nationalisation Act inter alia on the ground of infraction of Articles 14, 19(1)(f) and (g) and 31 Clause (2), but since the Nationalisation Act has been included in the 9th Schedule by the Constitution (Thirty ninth Amendment) Act, 1975, the petitioners also attacked the constitutionality of the Constitution (Thirty ninth Amendment) Act, 1975, for it is only if they could get the Nationalisation Act out from the protective wing of Article 31B by persuading the Court to strike down the Constitution (Thirty ninth Amendment) Act, 1975, that they could proceed with their challenge against the constitutional validity of the Nationalisation Act Now clauses (4) and (5) which were introduced in Article 368 by section 55 of the Constitution (Forty second Amendment) Act, 1976 and which were in force at the date of the filing of the writ petitions provided that no amendment of the Constitution made or purported to have been made whether before or after the commencement of that section shall be called in question in any Court on any ground and barred judicial review of the validity of a constitutional amendment (obviously, if these two clauses were validly included in Article 368, they would stand in the way of the petitioners challenging the constitutional validity of the Constitution (Thirty ninth Amendment) Act, 1975.