The Supreme Court on Tuesday referred to the constitution bench a challenge to the constitutional validity of the Adhaar scheme on grounds that it violates the right to privacy.The court indicated it may reiterate its March 2013 order of de-linking benefits under social welfare schemes with the possession of Aadhaar card.An apex court bench headed by Justice J. Chelameswar took note of the "apparent unresolved issues" while referring the matter to the constitution bench.The court indicated that it will direct the government to give wide publicity to its order that possession of Aadhaar card was not mandatory for availing benefits under the social welfare schemes.