Can it make sense for the UK to leave the EU over its principle of free movement of people? The answer is: no. Immigration is indeed a big issue, as is UK membership of the EU. But the former must not drive the latter. Both are too important for that.

Yet increasingly David Cameron, the UK prime minister, is boxing himself into a corner in his discussions with other members of the EU. This is largely a result of his party’s hysteria over the electoral success of the UK Independence party. It is also because a section of his party would welcome any excuse for leaving the EU. This blend of fear and hostility is driving Mr Cameron towards demanding derogations from the founding treaties’ principle of freedom of movement that he has no chance of securing. If he were to be prime minister after next year’s general election, he would have to campaign for a No vote in the referendum he would be mandated to call. Brexit is the likely outcome.

The news that the UK registered a 43 per cent year-on-year increase in net immigration in the year to June 2014 will add fuel to these flames. The figure of 260,000 for net immigration in the most recent 12 months exceeds that of any previous calendar year. It makes a mockery of the government’s promise to reduce net immigration to below 100,000. But the coalition did not have the levers to deliver on this promise, just as it will not be allowed to control immigration from the EU while staying inside. Promising what one cannot deliver is, as King Canute taught, folly. But Canute was trying to deliver a lesson. Mr Cameron was not.