RJD chief Lalu Prasad on Tuesday hit out at the central government over the withholding of data of the caste-based Census."This is a jung (war), be ready to fight it," the Rashtriya Janata Dal chief told party leaders here."Only after I, Samajwadi Party chief Mulayam Singh Yadav, and Janata Dal-United president Sharad Yadav put pressure in parliament, the central government decided to conduct a caste Census," he said.He said it was unfortunate that Prime Minister Narendra Modi's government was not ready to make the data public, and urged the "downtrodden and marginalized" people, Dalits and backward classes to fight for justice and rights.Lalu Prasad said Sharad Yadav will join his fast on July 26 in Patna to protest the withholding of the Census data, and called for a Bihar bandh (shutdown) on July 27.