The suggestion from Iain Duncan Smith that Mr Hammond should shut up or ship out is intellectually alarming. Do IDS and friends really want a Cabinet devoid of debate, ministers all adhering to a single orthodoxy on pain of being fired? That's a recipe for stupid, narrow government that makes mistakes and fails to reach out to those beyond its core supporters – something I'm sure Mr Duncan Smith would never want to bring about.

It also borders on the irresponsible at a time when markets and business are damagingly uncertain about the path the government will take through the next decade. I'm no expert, but I reckon the prospect of a finance minister being forced from office for the apparent thought-crime of advocating the single market would take at least three cents off the pound in a matter of minutes, not to mention the chilling effect on potential investment. I always thought these were things that the Conservative Party cared about, but perhaps Brexit has changed even more than I realised.

So Theresa May needs to do a little more than expressing via a spokesman "full confidence" in Mr Hammond, not least because of that phrase's unfortunate associations with political doom. She needs to make clear – in person – that she values full and frank Cabinet debate and all those who take part in it.