The children arrive, sweep the dust from the unfurled rubber mats, and get on with the business of learning.
There are no chairs or tables at the Under the Bridge School, no sportsfield or formal play area. Rather, lessons take place beneath a rumbling railway arch and children read off a blackboard painted on to a concrete embankment.
Yet from 8am onwards, six days a week, youngsters from nearby fields, the thin children of migrant agricultural labourers, start arriving for lessons, hungry for an education and a chance to break the cycle of poverty that has held back their parents.
“I work in the fields. I did not to to school,” said Bhauti, a 25-year-old woman with two boys at the school and who had come to check on them. “The children teach us. We used to make our mark with a thumb print. But the children have shown us how to write.”
India this week week heads to the polls in a month-long festival of democracy unparalleled in scale anywhere in the world. The campaign has so far been dominated by a debate over issues such a tackling corruption and economic development, and what direction India should take at this most important of junctions.
And a visit to this school on the eastern fringes of the nation's capital, close to the sacred Yamuna river, is a reminder that countless millions of Indians still struggle every day to obtain just the basics. Including education.
The school was established by Rajesh Kumar Sharma, a one-time building contractor, who started providing education for the children of his workers in 1997. Back then lessons were delivered in the fields.
Three years ago he shifted to this location, a space between a bridge that carries a line of the Delhi Metro rail network and its carriages full of office workers and students, heading into the city centre or east into the far suburbs. On the other side from where the youngsters sit is a highway and an advertising hoarding for an online sales site that urges people: “Turn your phone into a sell-phone.”
Mr Sharma receives no help from the government. The three or four teachers who come every day, including himself, receive no salary. He supports his own family with a small shop he runs with his brother.
Donations from people who hear about his school provide basic stationery and pencils for the 70 or so children. He has recently identified a location nearby where he wants to open a second school.
“There are lots of children who have just one parent and spend a lot of time working for food rather than going to school,” he said. “We think it is very important to sow a seed of education.”
In 2009, the Indian government passed the Right to Education Act, a piece of legislation pushed by Congress party chief Sonia Gandhi, which supposedly made access to free education a legal right.
Figures collated by Unicef suggest the act has helped boost the numbers of children enrolled in Indian schools and help reduce the number dropping out. “Tremendous progress has been made in the last four years in terms of inputs to universalise access to elementary education,” said Unicef's Ramchandra Begur Others suggest that for all the millions of rupees invested in the scheme, things are far from perfect. The media is full of stories of schools where teachers show up only to sign the register, of crumbling buildings and even of toxic lunches. A third of schools have no toilet for girls.
“It is unfortunate that the radical transformation of the schools and the larger educational system that was expected from the RTE Act has not happened,” said a recent report by Save the Children. It said there was a “silent crisis” within the education system and that the government had failed to “deliver on its own legal and constitutional commitments on a mass scale”.
Mr Sharma agrees. Having spent the morning at his school, most of the pupils head home, change into a government-provided school uniform and head to the local government school, where they spend their afternoon.
Mr Sharma is dismissive of what takes place there. Also, not all the children from migrant workers are able to register, making his school an essential fill-in. “They don't think at the government schools,” he claimed. “They sign the register but don't do anything.”
The children who attend Mr Sharma's classes, some of them so tiny they have to stand on piled bricks to write on the blackboard, belong to families who have poured into Delhi from across India, migrants driven by desperation or hunger. On the fringes of the capital they occupy the lives and spaces nobody else wants.
Many of the migrants who live close to Mr Sharma's school work as labourers on patches of fertile land that abut the Yamuna. There they grow spinach, herbs and fields of bright golden marigolds that are sold for use in religious festivals.
Bhauti, her husband, Jagdish, and their three children came to Delhi a few years ago from Alwar in Rajasthan. There was plenty of land there, she said, but no water. In Delhi she earns £1.20 a day in the fields while her husband makes £2 selling flowers. “There were days when we had no food. At least here there is work and we are able to send our children to school,” she said.
Her sons, seven-year-old Deepak, and Suraj, aged six, attend Mr Sharma's Under the Bridge School in the morning. Her daughter, Mamata, attends the government establishment. Deepak said he liked Hindi, while Suraj claimed English was his favourite subject.
Mamata said she liked going to school and meeting her friends. She said she liked all the subjects she studied and found all of them equally easy.
Sitting on a rope bed outside their shack, set amid the marigolds, four goats chained to a peg, Bhauti and Jagdish, outlined the problems facing India's poorest. The price of everything was rising, they said, especially food. They realised all too well the problem of struggling for all-important identity cards that provide access to government services.
The couple were registered to vote in Rajasthan and Bhauti claimed they would make the journey by train and bus to cast their vote. She believed she was going to vote for Narendra Modi, the controversial leader of the opposition Bharatiya Janata Party (BJP). “We will only vote for those who help us. We will vote BJP,” she said.
Her husband was less certain. He had raised the same problems as as his wife - inflation, the lack of security faced by migrants - but he said he had not yet decided who to vote for. He was aware of Arvind Kejriwal and his anti-corruption Common Man Party, or Aam Aadmi Party.
For now the couple's priority was to keep the children at school. “We will not let them work in the fields. We did that - that is enough,” said Jagdish.
Sitting among the flowers its was possible to believe in the dreams the couple held for their sons - why indeed, should they not become doctors or engineers. But there were fewer ambitions for Mamata. They would keep her at school until they could arrange her marriage.
Why could Mamata not also be a doctor? Bhauti shook her head. “That does not happen in our family.”