P Chidambaram, in Tihar Jail, asked his family to put out tweets on the matter on his behalf. (File)

Senior Congress leader P Chidambaram today took a swipe at Prime Minister Narendra Modi over his "Einstein challenge" to students, asking when would the country's universities become havens of freedom of thought and expression.

P Chidambaram, who is lodged in Tihar Jail since his arrest by the CBI, asked his family to put out a series of tweets on his behalf.

"I am happy the prime minister has thrown the Einstein challenge to students. Albert Einstein's celebrated quote was 'Freedom of teaching and of opinion in book or press is the foundation for the sound and natural development of any people'," he said.

"When will our universities truly become havens of freedom of thought and expression," he asked in a series of tweets.

The prime minister, in an article written by him in New York Times, had proposed the "Einstein challenge" to ensure that ideals of the Mahatma are remembered by future generations.

"As a tribute to Gandhi, I propose what I call the Einstein Challenge. We know Albert Einstein's famous words on Gandhi: 'Generations to come will scarce believe that such a one as this ever in flesh and blood walked upon this earth'," he had written.

"Mahatma Gandhi's personality. The power of his thoughts. His global impact. And, a special Einstein challenge for you all," PM Modi had tweeted on October 2 attaching his article on the occasion of Mahatma Gandhi's 150th birth anniversary.