Like many of us these days, Aviah Day, a university lecturer and activist with the east London chapter of Sisters Uncut, spends a lot of time on Zoom. On the 29th of March she got onto a call with community organisers across Europe and the United States. "I think someone from Kolkata was there too," she says. "It was wild, to be honest – complicated and messy, but also really rich and amazing."

The people on the call were all responsible for co-ordinating local responses to the coronavirus pandemic in their respective towns, cities and villages. They were there to share tips with each other, to offer cross-border emotional support. The call took a few hours to organise and maxed out at 100 participants.

Day, who is part of a mutual aid group in Hackney, was told by her counterparts in Italy and Spain – who at that point were further down the road than we are in Britain – that she needed to start thinking about ways in which her group could provide large amounts of hot food to her neighbours. As the virus infects more and more people, and as they become more seriously ill, the need for prepared meals grows, with fewer residents able to cook.

Volunteers from the Islington Covid-19 Mutual Aid group preparing food parcels for a weekly distribution to members of their community who are in self isolation and experiencing financial difficulty

It's just over a month since a group called Covid-19 Mutual Aid UK sent out a press release announcing the formation of over 200 community support groups, set up so that neighbours could help each other out with food deliveries, prescriptions, dog walking and anything else they might need.

Today, there are 3,447 groups across the UK, with an estimated 4 million people involved. Community resources and capabilities are being pooled. The traditional charitable distinction between the helper and helped is breaking down. Day, who is 32, tells me about a single mother in Hackney who was "so resistant to getting support. Someone dropped off some shopping for her. And then the next day she picked up an old man's prescription. She doesn't have money, but she can get out, pick up this man's prescription and take it to his house."

That kind of help is invaluable for the seriously ill and the elderly. Across the country, requests are varied, vital and at times poignant. One terminally ill woman in Islington told her mutual aid group that her last request was for a milkshake. The group brought her a strawberry one with all the trimmings from Creams.

At a national level, the mutual aid groups are organised into an Excel spreadsheet. On a local level, they are run across social media and instant messaging services. They are non-hierarchical, partly out of necessity: if one person controlled the group and then got sick, it wouldn't function. Leaflets telling residents about the groups were mostly distributed before lockdown.

In Leeds there are 27 neighbourhood groups, stretching from the inner city to the leafy suburbs. Riley Coles, 32 and a volunteers' manager for a refugee charity, is part of two mutual aid groups, one in Chapeltown, where they live. In this multicultural, working class area just north of the city centre, there are a lot of nurses and paramedics working through "scary times", Coles says. The group pushed for key workers in the NHS to be provided with the personal protective equipment (PPE) they needed. One health worker had to ask the group if anyone had any safety goggles – they weren't being provided with them at work. "I shouldn't be digging through my kid's toys to see if there are any goggles," Coles says. Eventually, a neighbour found some – "from some kind of craft thing".

Health workers are also a key concern in Machynlleth and the Dyfi Valley, in Wales. "We have assembled a team of people to manufacture PPE and will be providing 250 visors to help protect frontline workers," says Sam Maher, a 44-year-old communications consultant and local café worker. Maher is one of the 500 or so people who have signed up to Machynlleth Corona Community Response (MCCR). The visors are made digitally with 3D printers and laser cutters, as computer aided designers and engineers work together to protect medical workers.

Mutual aid group members delivering leaflets in Islington, North London. Photo: Jonathan Perugia / Gaia Visual

In Machynlleth, a central helpline has been set up, providing support between 9AM and 5PM, with volunteers taking calls directly from people requiring assistance. Support requests have mostly been for food and prescriptions, says Maher: "Due to our location, we are only covered for online shopping by two of the major supermarkets, and delivery slots are booked out weeks in advance."

The first group to organise under the Covid-19 Mutual Aid UK banner was made up of a group of friends in Lewisham, south-east London. The concept of mutual aid is part of a left-anarchist tradition, brought to a wider audience by the Russian thinker Peter Kropotkin in the late 19th and early 20th centuries. While social Darwinists declared that life was a case of the "survival of the fittest", Kropotkin made an anti-capitalist case for mutual aid and voluntary cooperation.

In Leeds, Riley Coles laughs when I ask if most people in their group share their political outlook. "No, I don't think most people share my politics. I'm an anarchist," they say. "Anarchism and mutual aid is familiar to me, whereas, for a lot of folks, it's new. There are people in mutual aid groups who are Tory voters. People aren't really thinking about party politics."

Sam Maher says something similar about mutual aid groups in the Dyfi Valley. "Some people are generally supportive of the government and believe they are doing the best they can in an unprecedented and difficult situation," she says, whereas others are angry at the government's response and the preceding years of damage done to the health service by austerity.

Nevertheless, as Coles says, "A lot of people are finding for the first time that the government isn't providing everything they need." For example, the labyrinthine process of applying for Universal Credit could be an eye-opening first experience of welfare bureaucracy for many, and one that leaves you in the end with hardly enough money to feed yourself.