A day after Kerala Assembly passed a resolution seeking withdrawal of the citizenship law, Prasad said there is no escape from the implementation of the law, and emphasised such a procedure is against the Constitution.

"I want to gently remind these parties (who oppose the law), to seek proper legal advice. Article 245, 256 and other provisions state that Parliament has the complete power to pass laws regarding naturalization and citizenship," said Prasad.

The Chief Ministers of nine states, including Kerala's Pinarayi Vijayan, have opposed the law and refused its implementation.

According to the Article 256 of the Constitution the states are obliged to comply with the laws made by Parliament, cited Prasad. He also added that due to vote bank politics many state governments are claiming that they would not implement the citizenship law.

The law, for the first time, introduces religion as a test for the citizenship.

The government says the law will help minorities in the three Muslim-dominated neighbouring countries - Bangladesh, Pakistan and Afghanistan -- to avail citizenship if they flee the country and seek safe haven in India due to religious persecution.

Whereas the opposition parties say this is a deliberate discrimination against the Muslims and violates the essence of the secular principals of the Constitution.

Prasad said that both houses of the Parliament discussed the law and then passed it, and the law has to be implemented.

"All governments talking about not implementing the law, need to know that once they have taken oath, they are bound by the Constitution," he added.

59 petitions have been filed in the Supreme Court challenging the constitutional validity of this law. The Supreme Court is scheduled to begin hearing on the matter on January 22.