Wellington House is in north Brighton, and known to the people who frequent it as Welly. It has the austere look of an old Victorian school, but what goes on inside is all about care and empathy. The building is the home of the city’s last council-run day centre for adults with complex needs, autism and learning disabilities, 21 of whom are reckoned to be regular attenders. One of its “service users” has been going there for 40 years; another has clocked up 24. Many of them know the staff as friends and confidants; for their carers, the time they spend at Wellington House represents precious respite.

That is the human picture; the accompanying tale of budgets and bureaucracy is altogether harder and colder. After five other council day-centre closures in the city over the past 20 years, Welly may well be on its way to the same fate. Brighton and Hove city council says its proposed shutdown will save £400,000 a year, and it will ensure that everyone’s “individual needs” are met elsewhere, thanks to schemes and services provided through what it calls “the independent sector market”.

On paper, that might make complete financial sense. But caring for adults with special needs – who often require one-to-one support – is always expensive, and the imperatives of balance sheets say nothing about people’s needs for stability and consistency. The community of carers and their supporters protesting against the planned shutdown have one key question – is complete closure really the only option? – and a long list of other complaints, not least what they say is the unsuitability of the alternatives they’ve been offered, which may result in people having to be placed in way more costly residential care.

The council says it is “confident that the range of providers overall will be able to adapt and meet the needs of the individuals”; its cabinet member for adult social care, Labour’s Mitchie Alexander, insists she and her colleagues “understand this is an unsettling time for everyone connected to Wellington House, but no final decisions have been made”. The official consultation closes on 7 July: the council, she says, is “reviewing” what happens there to “ensure we continue to provide people with the support they need alongside getting the best value for money”.

Others scent a fait accompli. Lou Vaughan is one of the organisers of the anti-closure campaign, which will be protesting outside Hove Town Hall on Monday. Her autistic brother, Matt, who’s 39, has been going to Welly for 10 years; the staff there help him pursue a deep love of gardening and vegetable-growing. “Like any autistic person, any transition for Matt isn’t simple,” she tells me. “There are so many micro things to worry about.” As and when the closure happens, she says it will be “devastating”.

As Andy Burnham prepares to take power, he is keen to accelerate work on the huge problems that the Brighton story might look like one tiny, tangential part of. His focus on England’s adult social-care system goes back to his 11-month spell as health secretary in the twilight years of the Gordon Brown government, and his launch of the idea of a national care service on a par with the NHS, a proposal cruelly kiboshed by the incoming coalition government.

“It is urgent, the need to fix social care,” Burnham recently told my colleague Pippa Crerar, just as the Makerfield byelection campaign got going, adding a final purposeful flourish: “I wouldn’t flinch from it.” There is talk of the final report about radical change authored by the crossbench peer Louise Casey being brought forward from 2028 to later this year. Casey is looking intensively at care and support for disabled people, but, as ever, most of the debate she sooner or later will spark will be about anxious pensioners, and how any new system would or wouldn’t mean having to sell their houses to pay for places in care homes.

About a third of adult social-care spending in England goes on support for disabled adults of working age. Yet despite this, provision is increasingly overstretched, dwindling or nonexistent. As one learning disability insider said to me last week: “There’s barely anything for people post-19 across the country.” Figures for recent day-centre closures are hard to come by. We all know about libraries, youth clubs and Sure Start centres, but this story – as with so many involving disability – has happened in semi-darkness, partly because of a perception of day centres as the epitome of unfashionable “building-based care”, superseded by councils granting people personal budgets to buy their own support.

In 2018, ITV News found that the number of adult day centres – including facilities for older people – had dropped by (and read this slowly) 41% across England since 2010. Back in 2012, the learning-disability charity Mencap found that since 2009 almost one in three councils had closed day services of all kinds, charging was becoming much more common, and, for all the official promises of new models of care, one in four learning-disabled people who responded to its survey now spent less than one hour outside their home every day.

Many centres never recovered from the massed shutdowns triggered by the pandemic. Closures have recently been big local news in Bristol, Windsor, Mansfield, Oldham, Tenbury Wells, Burnham in Buckinghamshire and more. In rural Malton in North Yorkshire, parents and carers are fighting to save Cauwood, another facility that might defy fiscal sense, but that provides something indispensable. Eight people regularly use the centre, two of whom have been doing so since 1991. “But those eight people matter,” insists Caroline Garrod, whose 24-year-old daughter Natasha depends on the centre. “It’s their lives, and they go because they love it.”

The story is replete with a very British sense that progress for some must mean setbacks for others: the closure is intended to partly make way for a new sheltered housing development. But the parents and carers involved are battling doggedly, as such people always do. If you want a case full of more straightforward symbolism, there is the former day centre in Harborne in Birmingham, one of four closed as part of the city’s drastic recent cuts. It had about 60 regulars; the supermarket chain Lidl now has plans for a site once synonymous with friendship, care and the constant fight against loneliness and isolation.

As Burnham’s journey to Downing Street decisively began, I spent six days in Makerfield, talking to people about what kind of country they want to live in. “People should be kind,” said one woman on her way out of a polling station. She sounded almost surprised at her own words, and the implication that a renewed Labour government should set an example. Where necessary, day centres can and should be modernised, blended into the wider community, and renamed “hubs” if it makes any difference. But the point still stands: stopping the relentless shut-down of some of our most precious shared spaces would be a very good place for the Burnham regime to start.

• John Harris is a Guardian columnist