The real Brexit process is (at last) underway. For half the country, the triggering of Article 50 was a moment to celebrate: for me, it marked a bleak day. The task of unwinding Britain’s place in Europe is fiendishly complicated: time is desperately short and neither side is well organized. Voters have been given wildly optimistic expectations of what an ultimate deal might look like and first contact with the reality of losing preferential access to the single market may be traumatic. The timetable is even tighter than it looks. The EU wants to fix the divorce bill, Irish borders and the rights of EU/ UK citizens before even starting to look at a trade deal.

There may be long arguments about process. It is true that many voted to leave because they had felt that immigration was too high but I do not believe that Britain will be able to cut the numbers without damaging the economy. Mrs May is not just making the wrong choices by opting for a hard Brexit, she has also been downplaying awkward trade-offs. By telling the population of this country that we can maintain barrier-free access to the single market while stopping EU immigrants and ending the jurisdiction of the ECJ, she is saying that we can have our cake and eat it. We must remember that the highest barriers to entry to the single market are not tariffs or customs checks but non-tariff barriers such as standards, regulations and state-aid rules, the referee of which is, yes, the European Court of Justice. Is Mrs May stepping back from her other error, that no deal is better than a bad deal? Only partially: to revert to trading only on WTO rules would cause serious damage to Britain’s economy.

Furthermore, an acrimonious break-up would make it even harder to co-operate on things like foreign policy, defence and security. A proper transitional period during which existing rules would apply is likely to be highly necessary in order to avoid falling off a cliff. There is a possibility of a deal that minimizes Brexit’s harm but, in a negotiation against the clock where both sides start so far apart, there is also a big risk of one which maximizes harm instead.