In 2014 Gemma Morton, the headteacher of a large secondary school, told Education Guardian her school had helped to pay for the funeral of a student whose family couldn’t afford it, even after they had sold their car. Three years on, she has helped to pay for two more funerals. “When a child dies, nobody’s saved for it,” says Morton. “There is literally nowhere for families to go apart from the people they already know, and most of them are poverty-struck too.”

Over the past few years, as austerity has deepened, more schools and individual teachers are bailing out disadvantaged families because they simply can’t say no. The latest government figures show 100,000 more children propelled into poverty in just 12 months. There are 4.1 million children – nearly a third of the entire child population – living in households on less than 60% of the average income.

At Gill Williams’s primary school in the north-west of England, local supermarkets deliver bread and fresh vegetables three times a week, which are placed in the playground for parents to help themselves. There is rarely a crumb left.

Williams says it is not so much that poverty is more severe, but that it has spread. “It’s everybody. Your average family is like that now.” The core group of those needing support in her school is three times larger than when she became a head 10 years ago.

Evidence of hungry children is clear, say teachers. “You notice kids borrowing money from friends to buy food, kids falling asleep, kids saying they’ve got a tummy ache, and they didn’t have breakfast because Mummy didn’t have anything in,” says Morton. She has also seen children taking scraps from the school bins.

Heads in poor catchments notice a difference when they attend meetings at other schools. “If you go and see kids in two different areas, they’ll be noticeably different heights,” says Morton.

Georgia Easton, a secondary teacher, always carries a few pounds in her pocket for children who have “forgotten” their dinner money. “It’s heartbreaking,” she says. “Kids saying ‘I had one slice of toast for tea.’” She estimates she spends about £10 a week of her own money on food and other shopping for needy pupils. That’s £380 per year. Gemma Kay, a food science teacher, spends much the same. “You hear kids talking about how in the holidays their parents are going to the food bank because they relied on free school meals in the week. It’s just very sad,” she says. “With changes to benefits, you’d know parents were on less money.”

David Penrose, chief executive of a group of schools in the Midlands, says: “In the last seven years it’s got progressively worse as the financial climate has bitten, especially in areas of deprivation.” Explaining why he doesn’t want to use his real name – “I don’t want to embarrass or shame my community because it’s not fair and it’s not their fault,” – he cites schools buying shoes, socks and underwear, and also non-uniform clothes for students “so they could feel ‘normal’ at a weekend – because all they have is uniform – or so they can go on a school trip”.

Williams asked her leadership team to compile a list of the school’s recent expenditure on personal items for students and their families. It included school shoes, bus passes, uniform when the pupil welfare department said a child didn’t meet their criteria; a pregnancy test for a mother who arrived at school in turmoil; an entire food shop after a home visit when it was apparent there was nothing to eat in the house; a mattress for a child sleeping on a sofa; and a bedroom carpet when social services said bare floorboards were acceptable.

Her school has put aside a sliver of budget, known as the social inclusion fund, for crisis situations, which has to be repaid. The fund has helped to guarantee a child’s physical safety during a criminal trial, when the family felt in danger: Williams paid for a week’s rental on a caravan out of the area.

She also used the fund to install a safety gate in a family’s house after first trying and failing to fit it herself. “The children were unsafe without one and I couldn’t leave them another night in the space.”

She observes pointedly that the local authority was unable to help. Thresholds of need for support by social services departments have increased and emergency grant and loan funds have been cut.

“There was mum with two teenage boys who’d been made homeless and put into one room,” says Easton. “I took them to Asda and got new shirts, trousers and shoes. It came out of staff pockets because much as school wanted to pay, it couldn’t.”

As financial systems become more accountable, Easton observes, teachers can no longer “just go to the petty cash: you go to the supermarket and it’s £15 so you just do it. And kids say where’s the money coming from, and well, it’s coming out of my wallet isn’t it? Where else is it coming from?”

Morton points out that staff using their own money is not without potential problems. “I’ve had to tell off a member of staff for getting pizzas delivered to school. His intentions were wholly honourable, but it could have been seen as grooming,” she says.

There is no doubt in the minds of those who spoke to Education Guardian that poverty is affecting children’s education. “You will go through so many behaviour barriers before you’ll get to the real truth,” says Penrose. “It’s unbelievably embarrassing for that child.”

Kay, who often provides sanitary items, says: “I’ve known students who wouldn’t come to school if they were on [their period].”

She says the school where she taught until last year didn’t celebrate World Book Day because it was obvious families couldn’t afford costumes. She and Penrose both observe that in schools in deprived areas they’ve worked at, attendance goes down on occasions such as Children in Need because families can’t afford a contribution.

In an average secondary school, Penrose estimates, 30% more families struggle to provide clothes and food than was the case seven years ago. “Kids don’t even remember ‘before’, because they’ve never known it,” he says. And a recent analysis by the Equality and Human Rights Commission shows that a million and a half more children will sink below the poverty line by 2021 thanks to benefit changes.

“When parents come in and say ‘can you help’ they never imagine that they’re asking us personally,” says Easton. “They want the best for their children and they can’t provide it. As teachers, I think we’ve just accepted it. We do this job because we care, and if we have to put our hand in our pocket, then so be it.”

Names and some identifying details have been changed