It’s a general rule that when Conservatives are in power, Labour controls the councils of most cities and metropolitan boroughs. Sometimes, they’ve used these as places to test ideas that they would hope to be able to then apply in government—from as far back as the London County Council under Herbert Morrison in the 1930s, whose mass council housing programme and nationalised, integrated transport system provided an outline of the sort of things the 1945 government would do.

This pattern was ended with the “rate capping rebellion” of the 1980s, when both the Conservative government and the Labour Party leadership clamped down on local authorities who had decided to directly confront Thatcher by illegally refusing to spend within the fiscal strictures she had introduced. This came to a head at the conference in 1985, when Neil Kinnock used his speech to make a personalised and emotive attack on Liverpool City Council and its leaders. It won him a lot of press applause—though not, as hoped, the 1987 election.

In that, it contrasts with the recent fallout from the Labour NEC’s relatively polite censure of Haringey Council for the ‘Haringey Development Vehicle’, a plan to bundle up a huge chunk of a London Borough, including several council estates, shops and parks, into a joint venture with the Australian property developers LendLease.

But the pattern is similar. Recent actions at the top suggest that Labour wants a shift in local government, away from an era in which councils and developers (and, frequently, outsourcing companies like Carillion and Capita) were hand-in-glove, and where Labour councils worked—very consciously—more like development agencies than elected representatives holding businesses to account. Instead, they’ll be expected to work as a line of defence for places suffering under austerity, housing problems and poverty. This, then, is Corbyn’s “a Labour council!” moment—albeit done with relative tact.

Despite the press response, there is a surprising amount of unity around this shift, with a common message from Corbyn and John McDonnell, the far-from-Corbynite Shadow Housing Minister John Healey, and Mayors like London’s Sadiq Khan.

Just days after the NEC’s statement on Haringey, Khan made clear that on his watch, no council estate will be demolished or redeveloped without a ballot receiving the explicit consent of its residents. In doing so, he was supporting a key demand of campaigners in Haringey—and on other threatened London estates, like the Aylesbury, Cressingham Gardens and Central Hill—which had been bitterly opposed by many local councils.

If residents were to give consent in these and other cases, there would have to be an explicit commitment to replace every single lost unit of social housing with more social housing. The euphemistic “affordable housing,” which is currently pegged at 80 per cent of market rent, and which can in practice can mean anything from shared ownership to studio flats and is usually provided in redevelopment schemes like the “HDV,” would not be enough.

Alongside this came two more new policies: Corbyn advocated giving local authorities the power to immediately seize empty properties in order to redress the increasingly shocking levels of homelessness, while John Healey has said a Labour government would bring in legislation to buy land at its nominal price, rather than the inflated price when speculation is factored in. This policy of land seizure is so rabidly Bolshevik that it gained the immediate support of former Tory Planning Minister Nick Boles.

In that, these proposals are part of what Corbyn calls a new “municipal socialism,” the outlines of which can be seen in cities like Preston or Salford, which have focused on taking outsourced services back in-house, employing council workers directly and at a decent rate, favouring local businesses and creating co-operatives.

That new municipal socialism, though, still lacks a key part of Herbert Morrison’s vision: the ability to build council housing in large numbers. (Haringey, for instance, has returned millions of pounds in Right to Buy receipts to the Treasury, claiming it was unable to build. It is certainly true that, though some councils have managed to in recent years, there are severe restrictions on scale.)

This is not so much a problem in Preston, where demand is relatively low, but a massive question in Greater London or Greater Manchester. Where council housing is built today, as in the London Boroughs of Southwark and Camden, for instance, it is at best replacement of, or infill in the open spaces of, council estates, usually on already council-owned land. This immediately clogs up the waiting lists, and consists in moving around council tenants, rather than creating new ones.

That’s still implicit even in Khan and Corbyn’s fairer version of “regeneration”—it presumes that new council housing will be built on top of older council estates, rather than, as it was for a century, on newly acquired sites. Healey’s land acquisition policy would change that, but only after winning a General Election.

As it is, the massive bill local authorities will face while they remove flammable cladding—usually the product of outsourcing companies via New Labour’s much-praised “Decent Homes” renovation scheme—could lead to councils trying to do ‘fairer’ versions of the likes of the HDV, where they will continue to sell off land, but will try to commit developers to stronger social housing targets. Whether councils have the legal nous, or developers the financial interest, to really make that work remains to be seen.

As it is, there’s much to admire in these long overdue new ideas on housing, which until now had barely shifted since the Ed Miliband era. A lot of the urban policies that have been most destructive in the last 15 years, from the replacement of 1960s council housing with luxury towers in London to the demolition of entire Victorian streets in the North, would have been impossible under compulsory resident ballots. This is about the furthest limit the new municipal socialism can go without breaking the law. It remains to be seen whether that will be enough.