An entirely reasonable contention is that if we're to try and work out what it is that we should do we must start from some mutually agreed set of facts. It would also be useful if those agreed facts were the truth of the matter. Not starting from this point is going to be piling error upon misunderstanding.

At which point what joy that telling the truth is now considered politically unacceptable:

Philip Hammond has declared that public-sector workers are “overpaid”, as a bitter cabinet war erupted over austerity.

At a heated cabinet meeting on Tuesday, the chancellor refused to lift the 1% cap on wages for public-sector workers on the grounds that they earn more than those in the private sector, along with generous taxpayer-funded pensions.

But Hammond left his colleagues thunderstruck at the language he used. “Public-sector workers are overpaid when you take into account pensions,” he declared. The chancellor then described train drivers as “ludicrously overpaid”.

The comments will fuel public anger that the Tories are out of touch with the public mood and will plunge Tory MPs into despair at the chancellor’s political tin ear.

The point being that this is actually true. As one of us has described elsewhere recently, since 2002/3 public sector pay (not including pensions and other perks) has gone from roughly comparable to private sector, risen faster in Brown's boom years and fallen less since the recession. Yes, of course, this is after controlling for age, qualifications and so on.

It's also entirely true that public sector wages have fallen in real terms since the recession - but then so have private, the private by more. These are the facts of the matter. Only once we all agree them can we then start to have a reasoned conversation over what we should do next.

But what chance of that when uttering such truths is regarded as politically unacceptable?