31C. Saving of laws giving effect to certain directive principles.
Notwithstanding anything contained in article 13, no law giving effect to the policy of the State towards securing [all or any of the principles laid down in Part IV] shall be deemed to be void on the ground that it is inconsistent with, or takes away or abridges any of the rights conferred by article 14 or article 19; and no law containing a
declaration that it is for giving effect to such policy shall be called in question in any court on the ground that it does not give effect to such policy:
Provided that where such law is made by the Legislature of a State, the provisions of this article shall not apply thereto unless such law, having been reserved for the consideration of the President, has received his assent.