Near the tills, in what looks, at first glance, like a standard convenience store, is a shelving unit crammed with goods, all bearing a familiar high street logo. There are packs of flour and jars of pitted black olives, tins of mixed bean salad and boxes of mushroom soup sachets. Hanging from the front is a laminated sign. It reads: “20 for 20.” Below that it says: “20p for all Waitrose Essential.” Gary Stott, the stocky Lancastrian responsible for this offering, picks up a tin and waves it at me. “Our customers do like a bit of Waitrose.” He points to the notice at the bottom of the sign that reads: “So that we can be fair with all our members please buy one item each.” People keep to it, Stott tells me. “All our members understand the rules.”

Both the membership model and low prices are what distinguish the Community Shop, housed in a low-slung building on a tidy housing estate in Athersley, to the north of Barnsley in South Yorkshire. It is an example of a small but growing group of enterprises known as social supermarkets. If you meet the membership criteria, loosely based around the grinding struggle of low income and scarce resources, you are granted access to shelves of surplus food from mainstream retail outlets at major discounts.

There’s chicken liver and bacon paté from Sainsbury’s for 45p instead of £1.30, alongside Tesco own-brand sauces for 50p rather than £1 and loaves of Warburton’s finest for 20p, which could be a fifth of the usual price. There are around 750 households using this Community Shop, though as many as double that can go through in any one year.

“For those who have the responsibility of feeding a household, it can save on average £212 a month on shopping bills,” says Stott, who has worked in the voluntary sector for decades and who, in 2013, helped launch the first of four Community Shops. The original, in Goldthorpe, South Yorkshire, is also believed to have been the first in the UK, though they have existed across the rest of Europe since the 1980s.

While the model varies from place to place, social supermarkets are distinct from food banks in that users pay for their groceries, albeit at large discounts. Whatever form it takes, the fact that they are spreading can be seen as a mark of the brutal impact of food costs on many families. According to recent UN figures, 8.4 million people in the UK are food insecure and 5.6% of those aged over 15 have said it is a struggle to get enough food. Perhaps it’s no surprise then that dozens more of these social supermarkets are due to open across the UK over the next year.

Some of our food went to food banks. But the need was like a fire. And nobody was trying to put it out John Marren

Community Shop is a sister organisation to Company Shop, a business founded more than 40 years ago by Yorkshireman John Marren, which trades in surplus or unsaleable products from mainstream food producers: items with misprinted packaging the supermarkets can’t accept perhaps, or which don’t have enough shelf life to make it into mainstream retail. Until the Company Shop came along, that surplus would either be sold for pennies on site to the firm’s employees or sent to landfill. Marren’s innovation was to purchase all of the companies’ surplus product, pool it in one place and sell it at a discount to employees of those companies. Company Shop now shifts 70m units of surplus food a year.

“We’d supported charities for a long time,” Marren tells me over a lunch made from surplus food at his headquarters in Barnsley. “Some of our food went to food banks. But the need was like a fire that was getting bigger and bigger. Nobody was trying to put the fire out.”

What he wanted to do, he says, was reduce the demand for charitable donations by creating an intervention that helped people before they reached crisis point. “I wanted to help people make a step change in their lives.”

John Marren, right, founder of Community Shop, with manager Gary Stott in the Athersley store. Photograph: Gary Calton/The Observer

Gary Stott, who had run a homelessness charity, came on board as a consultant for two weeks. That was seven years ago. Now many of Company Shop’s suppliers donate surplus that can either be sent direct to the Community Shop, or sold to members of the parent company, the profit from which is used to buy stock for the Community Shop. Company Shop provides all the logistics and back-office support for its charitable twin.

Talking to the customers at Athersley, there’s no doubt the shop helps. “I come in daily,” Jade tells me. “It’s low price and the people who work here make you feel welcome.” A couple are filling their basket with a mixture of breakfast cereals, bread and cheese. “I’ve been coming here for about three months,” Michael says. “My mum told me about it.” He admits you can never be sure what will be there from one day to the next. Sometimes there are certain brands; sometimes there aren’t. “You just have to be flexible,” he says.

It would be easy to focus solely on stacks of cheap, mislabelled soups or shelves of chocolate cakes once destined for the Christmas market, but still in date and now sold at a sixth of the price. But there’s much more going on here. Any profit generated on this side of the building goes to fund the Community Hub on the other side. That houses a kitchen serving lunch for £1.50, as well as spaces for a range of mentoring, training and support schemes.

“In reality, the shop is the gateway,” Stott says. “Our vision isn’t to sell cheap food. It’s to build strong individuals and confident communities around food.”

Lunch prep in the Community Kitchen. Photograph: Gary Calton/The Observer

In the Community Kitchen the group runs cookery classes, so members have the skills to cook from scratch. They have days where people make dishes from their own culture. “It’s a brilliant way for people to get to know each other,” Stott says. Members are trained to become community leaders, who then pass on skills in everything from managing a household budget, through launching micro-businesses to literacy. “We want to focus on what’s strong, not what’s wrong. You work with what you’ve got,” Stott says.

The real problem they are challenging, he says, is the narrative around “food poverty”, a term he detests. “Food poverty creates the idea that there’s just one thing that needs fixing. Is this enterprise about getting calories to poor people so they don’t die between now and next week? No, it really isn’t.”

I ask him whether playing with language can alter the reality. “Language can’t disguise poverty,” he says. “But it can create a different ground to grow things in.”

Over on the other side of the Pennines in Stockport, south of Manchester, there’s a different social supermarket model. There are four small food outlets called Your Local Pantry, each open for half a day a couple of times a week. They are run by Stockport Homes, which manages the council’s social housing. “Stockport Homes recognised that welfare reforms, including the bedroom tax, were going to cause problems for many of their clients,” says Anna Jones, who was appointed food sharing officer in 2012 to devise a plan that might provide support. “We wanted something that would have a community impact and have an element of dignity for people using the service.”

Lauren Lambert and her daughter at a branch of Your Local Pantry in Stockport. Photograph: Gary Calton/The Observer

The first one opened at Hanover Towers, in the Lancashire Hill area of Stockport, in 2013. All the food comes from Fareshare, the charity that redistributes surplus food from producers and retailers. Members pay £3.50 each time they want to shop, which goes to pay for the Fareshare deliveries. For that they can take 10 items, split between three higher value products from the red-labelled shelves and seven from the blue shelves. The value of the food they get is worth many times more than the £3.50 fee. “Our pantries don’t claim to solve food poverty,” Jones says. “We’re a helping hand in tough times.” Around 100 households are members of each pantry at any one time.

At the pantry in the Bridgehall neighbourhood, a small shop unit tucked into a tight suburban parade, members wait their turn to browse shelves of soups and cereals, and freezers stocked with ready meals, including bags of oven-ready fried chicken from a well-known high street outlet. Any surplus money made is spent on fresh fruit and vegetables to supplement the Fareshare stock. Cat Gould-Vendyback, who is currently out of work, has been coming here for three years. “As a single person you can sustain yourself for a week from what’s here, as long as you’re not greedy,” she says. “It’s a way of boosting your economy if you’re careful.”

But as with the Community Shop, there is more going on in this space than just the filling of fridges and bellies. “Living on my own I’m very isolated, but I meet people here,” Cat says. “The volunteers who run it know me. This place kept me going when I lost my partner. I know I won’t be judged. The food is an added bonus.”

Your Local Pantry charges members £3.50 for a 10-item shop Photograph: Gary Calton/The Observer

As with the Community Shop, staff can also refer members for classes and mentoring, which helps to get them into work and away from needing the pantry. It’s a model that is being rolled out across the country by the charity Church Action on Poverty, which has lottery funding and grants to franchise up to 55 of the pantries in the first year in deprived areas.

The British social supermarket model seems like a civilised and civilising solution to two problems: the mainstream supermarket supply chain produces surplus food that would otherwise go to waste, and there are those on low incomes who need cheap food. Yet it’s not without its critics. In March, the Guardian published a letter signed by 58 leading academics and campaigners, who argued that the donation of surplus food by major retailers and producers merely burnished the reputations of big business, without dealing with the underlying issues of poverty. “Charitable food aid is a sticking plaster on a gaping wound of systemic inequality in our societies,” the letter said.

For the most part it referenced food banks. However, according to Dr Lopa Saxena of Coventry University, a signatory to the letter who last year co-authored the first major academic study of social supermarkets in Britain, many of the same issues apply. “Social supermarkets are a step up from food banks,” she says. “But they still don’t address the issues of poverty. A form of austerity retail is being developed, based around an intermediary market in surplus food.” She argues that the supply is unreliable and “risks becoming a chronic part of the poverty economy.”

Martin Caraher, professor of food and health policy at City University, who also signed the letter, agrees. “Anything that helps people is good. But it’s a sticking plaster.” Professor Christina Holweg, of the Institute for Retailing and Marketing in Vienna, who coined the term “social supermarket” in a major study published in 2011, says the British model is deformed compared with those in the rest of Europe.

“In the standard continental model, shoppers have to go into mainstream supermarkets to complete their shop,” she says. “It’s a mixed model, whereas in the UK they are very separate.”

Stott agrees with these points. “We do not want to create a world where you get a different retail offer because of your postcode,” he says. “We certainly do not want to create an alternative retail subculture.” The aim, he says, is for people to stay members for six or 12 months “and then say thanks for everything, but I’m off now”.

Lunch at the Community Kitchen. Photograph: Gary Calton/The Observer

The Community Shop only sets up in areas that have the highest deprivation. A little over three years ago it opened an outlet a few miles from my house in Lambeth, which, like so many London boroughs, is a patchwork of affluence and poverty. It is located in rented council buildings behind the recycling depot in Norwood. Outside, there’s an urban farm growing fruit, vegetables and herbs to be used in the kitchen or handed out when there’s a glut. There’s a shipping container from which abandoned bicycles are sold cheaply after being fixed up, and another is used as a training space.

I spend a morning there, browsing the shelves of the shop, stocked with everything from 20p loaves of bread to upmarket Daylesford soups. I meet locals who came here needing help to feed their families and who stayed on as mentors. There are dozens of languages spoken in Lambeth and here, in the Community Kitchen, is where they can meet to share stories over dishes from the countries where they grew up.

“This place isn’t just about food,” says Ann-Marie Donovan, who manages the operation. “It’s about people making positive changes.” Indeed it is. But in the world of the social supermarket, food is where it all starts.