Tracing the flow of power in Westminster and Whitehall is rather like calibrating the fluctuations in a set of floating exchange rates in the political equivalent of the money markets. In the strange country we are temporarily inhabiting – let’s call it “Brexitland” – nearly all the political markets seem to be moving against the Prime Minister. For example, in the space of three days last week, 12-14 March, Theresa May failed in her second attempt to persuade the House of Commons to approve her exit deal with the EU, four Cabinet ministers defied a three-line whip and drove a JCB through the wall of collective responsibility without being sacked from a Cabinet as leaky as a cataract, before she just clung on to her control of the legislative timetable by two votes.

We must, however, be careful not to treat the accumulated events as a permanent shift of the exchange rate in the relationship between the executive and the legislature. A future PM with a substantial majority in parliament and genuine authority among his or her ministerial colleagues would instantly restore the standard relationships of relative power – though the memory of their frisking in the paddock of discontent will linger long among MPs in the House of Commons.