Delhi's education minister has outraged many of the city's private schools by ordering them to reserve a quarter of their places for poor children.
The move follows a declaration by the minister, Amrinder Singh Lovely, that the government "had a social responsibility" and that it was time schools fell into line.
The directive could see the children of businessmen and bureaucrats studying alongside youngsters who live in slums without toilets or running water and who spend their days picking over piles of rubbish for recycling or selling cheap goods to help their families eke out a living.
The initiative is the first of its kind in a country where an estimated 30 million primary-age children do not attend school.
Mr Singh said most private schools in the city had been given land at concessional rates on the understanding that they would educate poor children for free. But so far schools have resisted the move, despite a High Court order.
The directive has angered many parents who object to paying to subsidise poor pupils.
Private school fees range from Rs15,000 (pound;187.50) a quarter to Rs25,000 (pound;312.50), compared with nominal state-school charges of between Rs7(8 pence) a month to Rs100 (pound;1.25) a month.
School managers said they were educating poor children through programmes run with non-governmental organisations after school hours. Some have argued that poor pupils would find it difficult to integrate into the mainstream.
One principal, who did not want to be named, said: "In this age of cellphones and branded lifestyles a child from an underprivileged background will find himself completely lost and alienated in a public school."
Some principals said such alienation could permanently damage a child's psyche and that waiving tuition fees did not address the whole problem.
"Students will need to be given free uniforms, extra classes and food so that they do not develop a complex," said AM Wattal, principal of Springdales private school. TR Gupta, president of Action Line, the organisation which represents private schools, said the directive was "arbitrary" and that schools would fight it.
Parents have argued that they cannot afford the resulting rise in school fees as many can barely manage to pay the current bill.
But Mr Singh said he was "determined" to ensure that a High Court order supporting the directive would be implemented.
"We owe it to society," he said.
Seema Gaikwad, co-ordinator for the Commonwealth Education Fund, which campaigns among parents and communities for more schools and is funded by the British government, said the initiative was a positive move but that more thought was needed about how to motivate schools.
Ms Gaikwad said she understood the concern about how poor parents would pay for extra-curricular events and how wealthy and slum children would mix.
"Such an initiative can only succeed if management and parents are very sincere in the effort to make it work," she added.