May has found out how much of a nightmare her Brexit talks are going to be

Some EU officials are already talking about a 'dirty Brexit', with no deal being reached during the two years of formal talks starting early next year

The PM with Jean-Claude Juncker at the European Council summit meeting in Brussels (Rex)

There’s something about food and European summits. As a lonely Theresa May spoke briefly about Brexit at the end of a five-hour working dinner of pan-fried scallops, crown of lamb and iced vanilla parfait, diplomats from other member states could not help resorting to gastronomic metaphors.

“An a la carte Europe is not on the menu,” one told me, warning that Germany and France would not accept the UK’s plan to “buy” single market access for key sectors such as financial services and cars by paying into EU coffers, while ending free movement for EU nationals. “You cannot have your cake and eat it,” added a senior official from another country.

That is precisely what May wants. At her press conference after her first EU leaders’ summit, she said that Britain wanted to choose how to “control immigration” but also to “trade freely in goods and services.” But the view of the other 27 members is that the EU’s “four freedoms” – goods, capital, services and people – are “indivisible”.

May insisted that Britain is “not turning our back on our friends and allies” by leaving, which is not how they see it. It was no surprise that she got a rather frosty reception in Brussels; she was, after all, in the bizarre position of joining a club and wanting to leave it at the same time. Her hard Brexit rhetoric at this month’s Tory conference appalled other EU leaders. In Brussels, she struck a more conciliatory tone, calling for a constructive approach that looked for “opportunities not problems” and a “smooth departure” that worked for both the UK and EU.

But her demand for Britain to play a “full and active role” in the EU until it leaves played badly with the 27, who have already held two meetings without her to discuss life after Brexit. There are bound to be more. May should let them get on with it rather than demand a seat at the table and threaten to block their decisions. Otherwise she will get an even worse exit deal.

The Brexit negotiations were always going to be complex, but the mood music in Brussels showed that they could easily become a nightmare for May, who acknowledged there would be “difficult moments”. Some EU officials are already talking about a “dirty Brexit”, with no deal being reached during the two years of formal talks starting early next year.

Even if there is an outline agreement, it will be crucial for Britain to strike a transitional deal so that trade with the EU does not “fall off a cliff” when the UK leaves, as there will not be time to reach a detailed trade deal by then. But the feeling among the 27 is that any transitional arrangements must not be so good for Britain that it has no incentive to make a long-term agreement. That could mean May having to accept EU free movement if for an interim period, which might encourage her to opt for a general election while the negotiations were still underway. Although she has repeatedly said that the election will be in 2020, she might not want to wait if she knows that migration curbs would not take effect immediately when the UK leaves in 2019.

Hopefully after her first summit, May will understand better the emotional commitment to the EU project among the 27 – something that Britain has never shared, and has consistently underestimated. This matters because politics could trump economics on the EU’s side of the negotiating table. Germany and France might decide that a short-term hit to their economies through reduced trade with the UK is a price worth paying to preserve their long-term strategic interests. May should view with scepticism the naive optimism of the Brexiteers who argue that it will be alright on the night because the Germans will want to sell their cars to us and the French their cheese and wine.

A united EU front against informal “talks about talks” has prevented May finding out what kind of deal might be possible. Her most likely ally, Angela Merkel, was unamused by Britain sounding out different parts of the German Government, and banned officials from even tentative talks. Merkel’s edict was: nothing doing until formal negotiations start next year, and that the “four freedoms” come as a package.

In turn, the other EU leaders probably learnt something about May: her Tory conference speech was not posturing to keep her party sweet, and she is determined to end free movement to the UK. Some EU leaders, like a small minority of Remainers in Britain, are still in denial about Brexit and hope the Government and public will get cold feet. After meeting May, they should know better. Brexit is going to happen.

However, EU leaders are clearly puzzled by what May wants from Brexit. No surprise, because she doesn’t know yet either, and her fractious Cabinet is divided over the crucial trade-off between single market access and control of migration. For now, May is embroiled in a phoney war with the EU. The real one will be much more bloody.