Not that it makes up for the appalling mess over social care policy – one of many great challenges facing the country in the coming decades – but we should be grateful for Theresa May’s efforts to liven up what was becoming a dull, overlong and unnecessary general election campaign. In one single step, or rather one misstep, the Prime Minister has put a spring in the heels of every Labour, Liberal Democrat and SNP canvasser in a marginal seat.

She has rendered satirical her claim to offer “strong and stable leadership”; she has made Labour seem competent, as well as compassionate; she has annoyed, frightened and distressed Tory-voting pensioners. In short, she has made a hash of things. That’s not very Brand May.

This unnecessary blunder, however, seems to have been a team effort, but not one orchestrated by a large team. In recent days it has become increasingly apparent that cabinet colleagues may have had little if any input into one of the more important policy announcements made by the Government of which if they are still nominally members. It is also unclear whether the relevant ministers and advisers in the Department for Work and Pensions (DWP) and HM Treasury were much consulted on the social care proposals contained in the Conservative Party manifesto. We know that the entirely sensible, balanced and consensual recommendations made some years ago by Sir Andrew Dilnot have been trashed, even though they have already been put into legislation, and Ms May voted for them.

Theresa May refuses to say what cap will be with 'dementia tax' climbdown

An accurate picture of this study in misgovernment has to include every important detail in the vista. First came the manifesto policy. This went down badly on the doorsteps, and there were open grumbles from all levels of the Conservative Party. The answer to that was that Ms May was indeed pursuing a “tough” policy, but at least she was being honest with voters about the care crisis and not promising something for nothing. Ministers, including Damian Green, the Secretary of State at the DWP, maintained that the policy would not be changed, although there would be a Green Paper as a basis for consultation.

Boris Johnson, though – a man with an unsure touch for most things except public opinion – subtly started the backsliding. Of course a U-turn on a policy not yet even implemented would have been doubly embarrassing; so the Prime Minister decided to pretend that “nothing has changed”. In which case the original policy still stands in all its vote-losing glory. Or it has in reality changed, but to what nobody can say. There is to be a cap or “absolute limit” on the costs of care, but at what level?

This concession, if such it is, will necessarily disproportionately benefit the wealthy. Sadly, there are many pensioner households in this country, owner-occupiers or not, whose estates will fall far short of even £100,000, and many more whose total assets would not be so very much more. There is a small number at the very top of society who need have no worries about the welfare state having to care for them. That leaves a very broad base in the middle, of people who do not consider themselves rich but whose homes, after successive bouts of inflation, could be worth a £500,000 or even £1m – now relatively unremarkable sums, in London and the south-east of England, at least.

These households are, by definition, rich; but there remains doubt about whether they should have to pay the equivalent of 50 per cent, 80 per cent, 90 per cent or more of their personal wealth as a form of modern death duty: the “dementia tax” as it has been successfully dubbed.

Like “death tax” and “poll tax”, it is an ugly label for an ugly thing. Ms May is too committed to her social care policy to abandon it entirely and revert to the Dilnot plan, but it is becoming so toxic that she needs to make such changes to it as to render it even less fair than the first policy she placed in her manifesto. What’s more, every tier of property wealth that she takes out of the scope of the dementia tax, the less money it will raise to pay for social care for all.

All these considerations had been carefully gone through by Sir Andrew Dilnot when he came to frame his review. In broad terms, that review had been accepted by all the parties – a rare and precious thing in long-term social policy. The Prime Mister and what seems to be a tiny cabal of poorly briefed advisers have wrecked the policy. Many pensioners will now feel they simply cannot afford to vote Tory.

Theresa May flustered by constant questions over 'dementia tax'

The fact that Ms May frequently states that it will only take the loss of six seats to deprive her of her majority sounds less like a threat than a tempting invitation to a more balanced period of government. Some may even be thinking back to the “strong and stable” coalition era of David Cameron and Nick Clegg.

Of more immediate concern to Ms May is that the electoral damage she has done. That cannot be repaired, if at all, until she is able to provide details about where the various thresholds will fall, compared to the situation now.

Rightly, the media will not rest until they have found those things out. Added to the abandonment of the “triple lock” on the old-age pension and the proposal to means-test the winter fuel allowance, again at an unspecified threshold of savings, this Government is looking too much like it has something to hide.