Indian activists have dared the head of the country\'s planning body to live on half a dollar a day to test his claim that it is an adequate sum to survive. Last week the Planning Commission said the amount is \"adequate\" for a villager to spend on food, education and health. But prominent campaigners Aruna Roy and Harsh Mander asked the panel chief, Montek Singh Ahluwalia, and members to either withdraw the figure or resign. Officially, 37% of India\'s 1.21bn people live below the poverty line. But there are various estimates of the exact number of poor in India and one suggests the true figure could be as high as 77%. But the Planning Commission recently told India\'s Supreme Court that an individual income of 25 rupees (52 cents) a day would help provide for adequate \"private expenditure on food, education and health\" in the villages. In the cities, it said, individual earnings of 32 rupees a day (65 cents) were adequate. Critics say this amount is extremely low and aimed at \"artificially\" reducing the number of poor. They argue that this will deprive millions of state benefits they would otherwise be entitled to. \"The right to food campaign challenges you and all the members of the Planning Commission to live on 25 rupees or 32 rupees a day till such time that you are able to explain to the public in simple words the basis of the statement that this amount is \'normatively adequate\',\" an open letter to the commission signed by Ms Roy, Mr Mander and various other activists said. \"If it cannot be explained then the affidavit [filed by the commission stating the figures] should be withdrawn or else you should resign.\" The Planning Commission submitted the figures after the Supreme Court asked the government to update its poverty line figures to reflect rising prices. The low figures, at a time when India has been struggling to contain inflation which is at a 13-month high of 9.78%, have been ridiculed not just by activists but also by many citizens. Many experts have said the income limit to define the poor was too low. And a World Bank report in May said attempts by the Indian government to combat poverty were not working. It said aid programmes were beset by corruption, bad administration and under-payments.