Congress general secretary Digvijay Singh said the Thackeray family itself belonged to Bihar and had settled in Dhar in Western Madhya Pradesh from where they migrated to Mumbai.
"If you look at the history of Mumbai, then it is a city of fishermen. Rest all have settled there from outside," Singh said.
Shivanand Tiwari, a senior leader of the ruling JD-U in Bihar, said the conduct of Thackeray is a challenge to the Constitutional authority.
Bihar minister and a BJP leader Giriraj Singh demanded a case of "treason" against the MNS chief.
BJP Chief spokesperson Ravi Shankar Prasad said, "The Constitution permits any Indian to settle anywhere in the country. This is what makes India. We all need to respect that constitutional mandate,"
"There is a "need to desist from confrontation" while working in political and social fields," said BJP spokesperson Mukhtar Abbas Naqvi.
RJD spokesman Ramkripal Yadav said people of Bihar have a constitutional right to live in any part of the country including Maharashtra while Bihar PCC President Chaudhary Mehboon Ali Kaiser said he has written to Maharashtra Chief Minister Prithviraj Chavan protesting against the remarks by Thackeray.
NCP General Secretary Tariq Anwar accused Thackeray of trying to strengthen his political base in Maharashtra by playing out regional politics.
LJP president Ram Vilas Paswan asked the Centre to take stringent action against Thackeray for making inflammatory speeches with an intent to spread communal discord.