From the Guardian, writer Jason Burke talks to one of the organizers of the march.
"Millions of people are living in slums, on railway tracks, under plastic sheets … They should have a piece of land to call their own. Others have to make way for factories, roads, airports, mines. I do not accept industrialisation at this cost," said PV Rajagopal, the veteran activist who leads the Ekhta Parishad organisation behind the march.
Rajagopal and his followers say they are inspired by the example set by Mahatma Gandhi and his ideal of a nation of self-sufficient villages. One aim of the march is to mobilise the hundreds of millions who have not benefited from India's 20-year economic boom. Today is the anniversary of Gandhi's birthday and a national holiday.
However, Gandhi's "vision is being rejected every day in this country", according to Rajagopal, who made his name by persuading bandits in central India to "lay down their arms" in the 1970s.
The march is an embarrassment for the beleaguered Indian government, a fragile coalition led by the Congress party.
Rural voters have traditionally voted for Congress and their support will be crucial in elections due in 2014. In recent years, the poor have increasingly turned to other, often local, parties.