Why would a government seek to undermine an institution that provides over 1m homes for lower-income families and builds around 40,000 properties each year for a mix of tenures? By any reckoning, England’s 1,700 not-for-profit housing associations, ranging from small community enterprises to large development groups, are generally a success story. The majority are charities.

After the global financial meltdown of 2007-08 they kept building while large house-builders effectively shut up shop and many smaller construction businesses collapsed. Over the past 30 years they have attracted £76bn of private investment.

Today, for every £1bn of public money, they lever a further £6bn in commercial loans and bonds. They are the living embodiment of public-private partnerships writ large.

Yet the government has declared war on associations in England. David Cameron last week described them in prime minister’s questions as an inefficient part of the “public sector”. It prompted an immediate riposte from their representative body, the National Housing Federation, which has its annual conference this week. “Housing associations are emphatically not part of the public sector,” it shot back. Not yet, anyway.

The charge against associations? First, ministers think they should be building more homes – a bit rich when the government has slashed the grant for affordable housing to such a low level that it’s barely worth considering. Second, ministers complain of the sky-high salary packages paid to some association chief executives.

For the government, associations are clearly rooted in another era, tinged with what some on the radical right view as a toxic political ingredient: social provision. But there’s another reason: unfinished ideological business.

For many in the sector, the onslaught displays a deep antipathy towards social housing among sections of the government

The sale of council houses was pursued with such vigour in the Thatcher years – and given a further boost by the 2010-15 Conservative-led government – that 1.5m homes have been sold with large discounts in what amounts to the biggest privatisation of all. Associations, meanwhile, have held on to much of their housing stock. Ministers want to enforce a sale with right-to-buy legislation soon to be unveiled. Legal clashes are likely. An ugly battle looms.

How do you force charities and private organisations, supervised admittedly by a government regulator, to begin selling their principal assets – namely a considerable housing stock – against their will through another round of enforced right-to-buy sales? Their business model is built on borrowing against the guaranteed rental streams from their properties.

Answer? The government takes on the collective debt of associations: a cool £60bn. Remarkably, ministers are said to be relaxed about this prospect. Last week the Office for National Statistics said it would consider a move to reclassify associations as public bodies when the new housing bill is published shortly.

To plug a financial hole in housing associations for right-to-buy sales, ministers have said they will be compensated with money raised by forcing local authorities to sell their most expensive housing stock when it becomes vacant. By this convoluted means, ministers promise that homes to replace those sold off will – somehow – magically appear at a later date. Ideology, in short, is trumping all previous evidence to the contrary.

In an analysis last week, the charity Shelter estimated that in one London borough – Kensington and Chelsea – this could mean 97% of council housing being sold. London’s Camden and Cambridge could lose half their stock.

For many in the sector, the onslaught against housing associations – some of which, to be fair, have been over-ambitious, straying from their core objectives – displays a deep antipathy towards social housing among sections of the government. The result will mean mergers initially, and takeovers, with larger organisations assuming responsibility for smaller, vulnerable ones. But at least one medium-to-large association is in trouble. It might not be the last.