Our story starts, as all good stories must, with the Housing of the Working Classes Act in 1885 – or, more properly, the Royal Commission that preceded it. Our unlikely champion in this cause was the then-leader of the Conservatives in opposition, Lord Salisbury, whose 1883 article pointed out that the “conditions of working class housing were injurious to the health and morality of the population”.

“It is perhaps needless,” he said, “to give a detailed description of the conditions in which houses are run up for the working classes. What is called ‘jerry building’ is too well-known to need evidence to prove its characteristics. There can be no doubt that the houses are built of the commonest materials and with the worst workmanship and are altogether unfit for the people to live in… There should be a simple power by civil procedure for the recovery of damages against owners by those that have suffered injury or loss by their neglect or default.”

The squalor in which millions were condemned to live had already been well documented by great social reformers and novelists such as Charles Dickens. By the second half of the 19th century, it was finally driving change. This included the forerunner of today’s Homes (Fitness for Human Habitation) Act, spelt out by Lord Salisbury, as well as the first generation of housing associations – the Peabodys, Octavia Hills and Suttons.

The drive for decent homes continued throughout the 20th century, as municipal housing came into its own and the private rented sector retreated. Housing was understood to be as critical to the health and wellbeing of the population as the other great pillars of the modern welfare state – the NHS, pensions, sickness and unemployment relief. And conditions improved, too slowly for many, but significantly nonetheless.

Another wake up call came in the 1960s. Slum landlords – including notorious names like Rachman and Hoogstraten, who operated in my own backyard in Paddington and North Kensington – took particular advantage of tenants denied choice and often access to social housing. New arrivals from the Caribbean and Commonwealth were especially vulnerable of course, but so too were a whole class of people often deemed insufficiently respectable to meet the threshold for council housing.

Eventually this created a reaction, including new homelessness legislation and a whole new wave of housing providers often deeply rooted in neighbourhoods – Paddington Churches Housing Association, Notting Hill Housing Trust. The private housing sector shrivelled and shrank.

50 years on, the world has changed once more. Social housing flourished, then was starved of investment during the Thatcher years, next enjoyed the massive boost provided by the Decent Homes Initiative under the Labour government, but has now been drastically eroded by Right to Buy and a failure to build.

Owner occupation soared then stalled as a crisis of supply and affordability hit hard from the middle of the last decade. And the private rented sector is back at scale, housing families with children and those in housing need now in numbers not seen for more than half a century.

While overall standards have continued to rise, one million renting households – some three million people, including many children – currently live in unfit homes that potentially threaten their health and their safety. Three quarters of these are privately rented homes – still the sector with the worst conditions – and one quarter are council or housing association.

Private tenants can turn to their councils for help with enforcement, but lack of resources, and in some cases, a lack of political will or interest, means that such enforcement is both highly variable and highly restricted. Council tenants don’t even have that protection, and as we approach the second anniversary of the Grenfell disaster, we are reminded again of what can go wrong and how proper safeguards and enforceable rights must be non-negotiable for everyone.

My Homes (Fitness for Human Habitation) Act – actually the idea of and written by the outstanding housing lawyers Justin Bates and Giles Peaker – reflects the same need to protect tenants that Lord Salisbury recognised as essential a century and a half ago. The scale of the challenge may not be as great, thank God, but a million people is far too many to still be at risk, and inevitably it is the least powerful and most vulnerable who are left stranded in the worst housing conditions.

Good landlords have nothing to fear, while tenants now have a new way to hold the worst to account. Giving tenants enforceable rights to a safe and decent home is still not enough, as even this government is starting to recognise. We need a new generation of social housing, of course. A restoration of legal aid, naturally. Protection against ‘no fault’ eviction, and more.

30 years on from the de-regulatory 1988 Housing Act, with all that has happened since, the moment is right for another sea-change in housing law and policy, focusing on security, affordability, quality and rights. But requiring homes to be fit for habitation is an important step in the right direction.

This piece was commissioned by Tom Copley, who is guest editing LabourList today.