In a dig at the ruling BJP, Samajwadi Party chief Akhilesh Yadav on Saturday said socialism is at the root of the great concept of "Ram Rajya" and it is possible only through a caste census.

Yadav's statement comes days after several opposition parties, including the Congress and the JD(U), demanded a caste census and sought reservation according to the population of SC, ST and OBC communities.

Congress president Mallikarjun Kharge even wrote to Prime Minister Narendra Modi, demanding an updated caste census. He said meaningful social justice and empowerment programmes are incomplete without such data. Bihar Chief Minister and JD (U) leader Nitish Kumar supported the demand by the Congress party.

In a tweet in Hindi, Yadav said, "Socialism is the root of the great concept of Ram Rajya. Socialism implements in a true manner on the ground principles like treating everyone equal without discrimination, embracing (one another) with love, giving equal opportunity to everyone and social security."

"Ram Rajya is possible only through caste census, which will deliver true social justice," he added. The demand for a caste census is likely to test BJP's outreach to the backward classes.?While the Bihar unit of the BJP had supported a resolution for a caste census in the state, the party's central leadership is yet to respond to the demand for it.