THERESA MAY had to say something about Brexit at her first Conservative Party conference as party leader and prime minister. She could not just repeat her tedious mantra that “Brexit means Brexit”.

So on October 2nd she came up with an uncharacteristically splashy pledge: a “Great Repeal Bill”, promised for the next Queen’s Speech, to translate existing EU legislation into British law and then repeal the 1972 European Communities Act that gives legal force to EU directives and regulations.

Yet for all the fanfare and the flamboyant title, such a bill, which will take effect only after Brexit has happened, is merely an automatic consequence of Britain’s departure from the EU. Far more significant was Mrs May’s other promise: to trigger Article 50 of the EU treaty, the only legal route to exit, before the end of March 2017. Article 50 sets a two-year deadline for a country’s departure from the club that can be extended only by unanimous agreement of all EU members. It is biased, allowing the rest of the EU to decide by qualified majority on the terms of exit without the departing country having a vote. Some Tories had duly been urging Mrs May to delay invoking Article 50, at least until after the second round of the French presidential election in May, or even after the German federal election next September.

By rejecting this advice, Mrs May has made it far more likely that Britain’s departure from the EU will take the form of a “hard” Brexit, with Britain leaving both the customs union and the EU’s single market. She hopes for informal discussions on the shape of Britain’s future relationship with the EU in the months before the invocation of Article 50. But her EU partners are likely to refuse to negotiate, especially given the febrile atmosphere that will surround the French election when it gets going in earnest in January. Even if they are prepared to talk, they will almost certainly maintain their current, tough position, which is that if Britain wants to keep its membership of the single market it must accept free movement of labour from the rest of the EU, continue paying into the EU budget and observe all current and future single-market regulations without having any say in making them.

Mrs May has made clear that, although she does not want to stop all migration from the EU, she does want Britain to have full control over whom it chooses to let in. That seems incompatible with the EU’s free-movement rules. Brexiteers are also unhappy with any suggestion that Britain might keep contributing to the EU budget, and they jib at the very notion that, after Brexit, Britain may have to observe the EU’s single market rules, which would in effect mean conceding some sovereignty to the European Court of Justice. Instead, the Brexiteers want a hard Brexit that would entail leaving the single market and either seeking a free-trade deal with the EU (like Canada’s) or relying simply on trade under normal World Trade Organisation (WTO) terms.

Most economists, however, reckon a hard Brexit would cause maximum damage to the British economy. A free-trade deal is unlikely to cover financial services, so banks would lose the EU “passport” that entitles them to trade from London across the EU. Britain would also face customs and rules-of- origin controls, as well as many non-tariff barriers, especially in services. Trading on WTO terms alone would imply tariffs for such key export industries as cars and pharmaceuticals. Carlos Ghosn, the boss of Renault-Nissan, has already said he needs a promise of compensation for any such tariffs if his company is to invest further in its Sunderland car plant, most of whose output goes to the EU.

A hard Brexit would not solve Mrs May’s internal party problems, either. She has a majority of only 12 seats. Europhiles in the parliamentary party in the Commons and perhaps in the Lords may oppose her. George Osborne, a former chancellor, has declared that Britons voted for Brexit but not for a hard Brexit. Mrs May will have enjoyed the enthusiastic reception that the conference gave to her promised great repeal bill. But the reality is that the splits within her party over the best terms for Brexit have only just begun.