The MSU said there were no Brus in Mizoram in the 1961 census while there were 9,828 Brus in the 1971 census and that many people belonging to the community illegally continue to enter the state from Bangladesh through Tripura.
"We accepted that Brus, who are Indian citizens can become good citizens and can stay in Mizoram, but the MSU held that illegal immigrants from Bangladesh could not be accepted," the memorandum, faxed to Chidambaram on Friday, said.
The MSU also urged the Centre to accept the Mizoram Trading Regulation Bill, 1991 in toto and increase the number of reservation in jobs for the Scheduled Tribes.
The memorandum also urged the Union Home Ministry to intervene in the border dispute between Mizoram and Assam and solve the long-standing border between the two neighbouring states.