India, March 6 -- A meeting of political parties in Tamil Nadu on Wednesday unanimously asked the Centre to use the 1971 Census as the basis for any delimitation for the next 30 years, ratcheting up tensions on a contentious exercise that has the potential to widen the chasm between India's northern and southern regions.

The meeting, presided over by Tamil Nadu chief minister MK Stalin but boycotted by the Bharatiya Janata Party (BJP) and its allies, was attended by members of 35 parties, including the All-India Anna Dravida Munnetra Kazhagam and the Congress.

After the meeting, Stalin also proposed a joint action committee (JAC) comprising parliamentarians and representatives from all southern states to create awareness among people an...