Like swapping her Vivienne Westwood tartan trouser suit for the geography teacher’s tweed jacket, Theresa May’s attempt to try on Labour housing policy makes an ill fit. Overturning decades of Tory tradition, May has promised to build “a new generation of social housing”, declaring that private housebuilders will never meet demand “without the active participation of social and municipal housing providers”. Municipal housing providers? It is the kind of throwback language of the welfare state that even Jeremy Corbyn dare not use.

As if trying to prove beyond all doubt that May is no Maggie, the Conservative manifesto appears, on the surface, to be a radical departure from the Thatcherite faith in the free market to solve the housing crisis. Even as recently as the February housing white paper, the government’s policies were focused on private-sector housebuilding, with measures designed to free up more sites for developers and getting them to build faster. But now the Tories are promising to enter into new “Council Housing Deals” with “ambitious, pro-development, local authorities to help them build more social housing”. And they even want to let councils pay a lower price for the land to build on, forcing landowners to give up their assets for less.

If it sounds like the kind of policy that will have hedge-fund managers choking on their cornflakes, then rest assured, things become more familiar in the sentence that follows. It is not so much council housing that the Conservatives are proposing to build, as “fixed-term social houses”, which will soon return to the market. These homes “will be sold privately after 10 to 15 years with an automatic Right to Buy”. As a result of four decades of right to buy, there are now 1.4 million fewer homes for social rent than before Thatcher’s victory in 1979. The result of this disastrous policy hasn’t been to emancipate a generation. It has simply been to erode a vast public asset, raise rents, increase house price inflation, widen the gulf between those who own their home and those who never will, and force cash-strapped councils to rent back their own properties at vastly inflated sums to house the most vulnerable. May’s policy won’t do anything to reverse this flow of public funds into private bricks and mortar. It will only accelerate the torrent.

And just like the rest of the Conservatives’ uncosted manifesto pledges, it isn’t clear where the money will come from to build this supposed “constant supply of new homes for social rent”. The plan comes with no new funding beyond the £1.4 billion for affordable housing (not social housing) already earmarked in the 2016 autumn statement – which promised just 40,000 new homes. There are no figures for how many more socially rented units the Conservatives plan to build, but the overall target remains as one million homes between 2015 and 2020, equivalent to just 200,000 a year. As the National Audit Office pointed out in January, that would actually mean fewer homes will be built over the next three years than were built last year. Some ambition.

Compare this with Labour’s pledge to build “at least 100,000 council and housing association homes a year for genuinely affordable rent or sale” by the end of the next parliament, and the difference is clear – although these plans aren’t costed either, so must be taken with an equally hefty sack of salt. Jeremy Corbyn has said that tackling the housing crisis is his number one priority policy, and this figure is suitably ambitious. It represents a 50% increase on the coalition’s highest output of building 67,000 homes in 2014/15, most of which were not even genuinely affordable. Shadow housing minister John Healey (for whom housing policy is, reassuringly, a hobby beyond his day job) has argued it would be eminently achievable if councils and housing associations were allowed to build to their full potential and developers’ Section 106 contributions were properly levied. He set out detailed plans for Labour’s building programme in reports for the Fabian Society and Smith Institute, which gives you an unusual level of confidence that a shadow minister knows what they’re talking about for a change.

Promising to transform the Homes and Communities Agency into a centralised housing delivery body, Labour says it would establish a new Department of Housing, presumably with its own dedicated minister, and remove the crippling restrictions on councils building their own homes for rent. There is a welcome raft of measures to improve the lives of the most vulnerable, undoing a range of Tory policies that have left thousands living in precarious situations and savagely displaced long-standing communities. It would scrap the Conservatives’ ban on long-term tenancies, abolish the bedroom tax and end the right to buy, except where councils can prove that one-for-one replacements are possible, as well as reinstate housing benefit for 18- to 21-year-olds, removed under the Tories. The manifesto is strong on homelessness too, promising to make 4,000 additional homes available for people with a history of rough sleeping. The Conservatives promise to halve rough sleeping in the next parliament – a pledge that only undoes the doubling that has happened on their watch – while Labour is committed to ending it. Under Corbyn, it is clear, more people would have a secure place to live.

But in many ways Labour’s plans don’t actually go far enough. The party strangely plans to continue the Tory “help to buy” policy for another seven years, an initiative that has been widely damned as simply underpinning the profit margins and dividends of the big housebuilders, and helping people who can afford to buy anyway.

Their timidity is also exposed by another surprisingly red-tinged Tory policy: the reform of compulsory purchase orders, allowing councils to buy land at below market value to build housing. As Daniel Bentley of independent thinktank Civitas points out, “it overturns more than half a century of land policy which has protected the rights of landowners to extract maximum profit at the expense of the rest of the community”.

The Conservative party manifesto goes on to hint at major land reform, as well as promising to digitise the planning process and compile an open database of land ownership, forming “the largest repository of open land data in the world”. “We will work with private and public sector housebuilders to capture the increase in land value created when they build to reinvest in local infrastructure, essential services and further housing,” it states, “making it both easier and more certain that public sector landowners, and communities themselves, benefit from the increase in land value from urban regeneration and development.”

Planning permission for development can increase land values as much as tenfold, producing an unearned windfall that has always flowed straight into the pockets of landowners. The Centre for Progressive Capitalism estimates that every year landowners benefit from £9.3bn of such windfall profits, which could be spent on supporting infrastructure investment and housing. It is extraordinary for the Conservatives to be proposing to intervene to reverse this tide – and equally impossible to see such reforms getting past the landed interests of their own party.

Capturing the uplift in land value for the wider community has been core Liberal policy since time immemorial, indeed The Land Song was the Liberal party anthem until the 1980s, so how do the Liberal Democrats fare? Oddly the Lib Dem manifesto doesn’t go into as much detail as the Tories’ in this area, although there is mention of considering land value taxation.

By establishing a new national Housing and Infrastructure Development Bank, the party claims it they will be able to increase housebuilding to 300,000 homes a year, almost double the current level. They will allow councils to end the right to buy, lift the borrowing cap to get them building again and target “buy to leave” empty homes with a 200% council tax. The Lib Dems will penalise land-banking developers with a “use it or lose it” policy, with a penalty on failure to build after three years of winning planning permission, and introduce a “community right of appeal” in cases where planning decisions go against the approved local plan. It’s a raft of policies that put power back in the hands of the people, promising real localism in action.

And perhaps most significantly, in response to seeing a generation interminably stuck in the private rented sector, the Lib Dems are proposing a “rent to buy” model, where rental payments give tenants an increasing stake in the property, leading to outright ownership after 30 years, as well as giving them first refusal to buy their home should the landlord decide to sell. As someone who has been renting the same house in Hackney for the last seven years, during which time the value of the property has doubled, it’s an appealing idea.