I have seen the future of housing for working-class Londoners, and it is frightening. It is a land of flats so broken that the children who live in them are hospitalised. Where families have to live among condemned electrics and mouse infestations. Where nails poke up from carpets, tearing the skin off babies’ feet, while parents are driven mad trying to get an apparently indifferent landlord to fix things.

All this is happening not in the 1960s but right now. Those rundown properties aren’t owned by some slumlord, but a Labour council.

Go see the future for yourself, at Custom House – that stretch of the East End where the beards and the bankers give way to massive conference centres and dead industrial estates. For more than a decade residents here have been living under the shadow of the wrecking ball – a multibillion-pound “regeneration” scheme announced in the booming noughties but still to begin in earnest. While waiting for the developers and coffee shops to move in, Newham council sublet more than 300 of its properties in this small patch of the capital to a big private landlord called Tando. And that’s where the problems begin.

I recently spent an afternoon walking around Custom House, and everyone to whom I mentioned the name Tando told me horror stories. On their request, I shan’t give full details, but all were youngish women with children, shifted off Newham council’s waiting list into a Tando home. They were told that the flats were newly done up – yet when the mothers moved in, what they say they found was broken toilets and dodgy plumbing, and homes too draughty to bring up young children in.

Lavinia relates how her flat had a gas leak that forced her to stay with her mum. Shaheda says she found a flooding toilet and sharp nails poking up through the carpets that would puncture her toddlers’ feet. Their complaints would apparently go unanswered, sometimes for days, and then when repair men came, their work would amount to cheap bodge jobs. Temi kept complaining about a leak coming into the downstairs toilet: each time a workman came, he would only patch things up, never fix the problem. The leak spread, as did the mould. She recalls how, one day, while her boy was in the toilet, the ceiling came crashing down.

Imagine you are one of those mothers, promised a new home that turns out to be a pit of dangers. You phone the repairs service only to get an engaged tone or to be shouted at (something that the women kept mentioning). Meanwhile, you and your young children have to endure things that no family living in one of the richest cities on the planet should have to suffer.

From day one, Shaheda’s windows let in so much wind that the entire family would have to swaddle themselves in coats and jumpers – and even then “it would feel like winter inside”. Just before her youngest was born, she says she pleaded with Tando not to put the newborn through this. Her baby kept catching colds, had difficulty breathing, would fall asleep but wouldn’t wake up. The boy was kept in hospital and put on steroids and a nebuliser. The lasting trauma of this and other episodes in the flat, she believes, has been to make her son withdrawn, scared to be without his mum and dad.

Even as she recalled the details, tears came to Shaheda’s eyes.At the time, the 30-year-old came “close to a breakdown”, crying constantly and unable to sleep. One thought tortured her: “Because of these poxy windows, my son’s suffering so badly. I can’t get help from anyone. I can’t do anything.”

Forget Downing Street speeches on social mobility: if we want our children to be and do the best they can, we must give them decent and safe homes. But what these women were describing was squalor – of a kind that Henry Mayhew and the other Victorians would have recognised. That squalor made a mockery of their attempts to get on and bring up their families. While graduate Lavinia shared her dreams of becoming a social worker, raising the kids well, perhaps one day buying a house, I looked around at the baby photos and the signs reading “Eat Your Greens” and “Family: Where Life Begins and Love Never Ends”. What chance did she give to achieving those sensible, modest goals? “Not likely.” She, her family, and all their talent and promise are being squandered.

Who pays for this dilapidation? Us, the taxpayers. Although the flats are public property, Tando sets the rent. It is of course much higher than council charges – and it is largely met through our housing benefit bill. Even while paying far more for much less, Lavinia and her neighbours have none of the security of tenure routine for Newham tenants. Lavinia started on a year-long tenancy, but it now rolls over from week to week.

Insecurity at the bottom, booming business at the top – coupled with convenient denials where it matters. Newham council told me that it “closely monitors the service provided by Tando”, and that officers “meet regularly with the directors” of the company. Yet despite the stories above and many others like them, Newham has not only renewed its contract with Tando for another few years but handed it another 210 units to manage. Tando director Harry Antoniou told me that the vast majority of tenants are very satisfied with their accommodation. He did admit to issues with a small group of tenants but claimed they were “historic”.

But if that’s the case, it’s probably because the tenants have, together with community activists’ group Peach, spent months protesting their conditions. Last month they finally met Antoniou. Since then Tando repair men have begun putting things right. In 21st-century London, it apparently takes a mass rebellion to get a functioning sink.

Meanwhile, Tando’s parent company Omega is expanding into the rest of the country, and is now Birmingham city council’s “social lettings agency” – shifting residents there off the waiting list into private rental accommodation. And Omega was bought in 2014 by Mears – a company that specialises in outsourced social housing and care for the elderly – for around £40m.

Remember that this is happening in a London borough whose mayor, Robin Wales, allegedly told a young woman a couple of years ago that “if you can’t afford to live in Newham, you can’t afford to live in Newham”. Remember that the supposedly socially aware Theresa May was part of a government that brought in the Housing Act, which will finally kill off council housing in inner London. Remember that the austerity programme Britain is still enduring is seeing a mass privatisation of remaining state assets – including public land. Then go to Custom House, because what you’re seeing there isn’t a one-off scandal: it’s the future.