Patna, Apr 13 (IANS): They may be bitter political rivals, but Lalu Prasad's Rashtriya Janata Dal (RJD) has thrown its weight behind Chief Minister Nitish Kumar when it comes to celebrating Bihar Day in Mumbai - an event that has turned controversial in Maharashtra.

"We support Nitish Kumar on his stand to attend Bihar Diwas celebrations in Mumbai," senior RJD leader and MP Ram Kirpal Yadav said here.

"In our federal structure, we are free to move across India and celebrate Bihar Diwas anywhere. Mumbai is not a fiefdom of Raj Thackeray's Maharashtra Navnirman Sena (MNS)," Yadav said.

The MNS, which has often protested migrant labour from north India working in Mumbai, has been bitterly opposing Bihar Day in Mumbai and even challenged Nitish Kumar to enter that city for Sunday's celebrations. This prompted Nitish Kumar last week to comment that he was "free to travel anywhere in the country and do not need a visa to come to Mumbai".

"Millions of Biharis worked hard day and night to construct Mumbai. The contribution of Biharis is no less than Raj Thackeray's," said Yadav, considered close to RJD chief Lalu Prasad.

RJD legislator Samrat Choudhary said: "Nitish Kumar has to attend Bihar Diwas celebrations in Mumbai to prove Raj Thackeray wrong."