Are RSLs public or private? Hard to tell.
Tne characteristic of this magazine is its civility. Its general tone of politeness reflects the world of social housing – you're a pretty kind and mutually respecting bunch. Elsewhere different rules apply. I am on the mailing list of a monthly called Health Care Management, a serious affair for NHS cadres. Its tone, however, is harsh and judgmental. Health secretary Alan Milburn and his special adviser Paul Corrigan are this month subject to savage personal attack – and not for the first time.

Perhaps that just reflects tensions within the NHS. Health is deeply politicised. Or perhaps it's because registered social landlords aren't public bodies that relations with government tend to be kinder, gentler – people don't go around slagging off Jeff Rooker or Nick Raynsford personally.

Paul Corrigan and his boss seem to be aware of this. They have been battling with the Treasury recently over the establishment of "foundation hospitals". The big idea here is that managers, cut free of central strings, would be more effective. Corrigan has worked up the idea from think-tank papers on "public interest companies". These are entities, outside the Industrial and Provident and charities acts, which would be required by law to pursue the public interest, but have the commercial freedom enjoyed by profit-making companies.

The leap of faith required for this to work is that private motivation and public purpose can be combined; that you can have private finance and social benefit. RSLs may well say that they are already doing this. They borrow extensively in the capital markets in order to build for social renting and pay executives at rates comparable with the private sector but within mission statements emphasising social purposes.

The significance of David Davis's declaration at the Tory party conference on right to buy for housing association tenants was the extraordinary act of nationalisation he was proposing for social housing. He effectively said that RSLs are public entities and should be subject to the same rules as other public entities such as councils.

Governments and housing executives have drawn a veil over the exact status of RSLs. Behind the housing conference quiz question "can an association go bust?" lies a theme that has come to the front of the political agenda: is the Treasury responsible for a class of organisations that claim they are independent of the state? This applies to RSLs and universities– both depend heavily on grants and income streams which the government subsidises. Are their assets alienable or are the banks that lend money to them assuming such organisations will be bailed out if they get into difficulty?

The Treasury is far from consistent in its approach. It turns out that borrowing by Network Rail is allowed to be off the books, but it insists that capital for the foundation hospitals is scored against existing NHS budgets. Councils are severely restricted in their borrowing, but RSLs do not have to make a pilgrimage to civil servants before entering a commercial contract.

Let's avoid too much clarity, you may say, because it could lead to more central control. But without clarity, we get interventions such as David Davis proposing to upset all existing understandings.

What he may have done is up the risk premium on loans to RSLs. Lenders will need reassurance that the asset base on which they are lending will not suddenly start shrinking if tenants buy.

Yet lenders could take a different view.

By asserting that RSLs' property is "public" property, the Tories may inadvertently have assured lenders that RSLs are as safe as local authorities or the Treasury itself.