LESS than two months are left until the October European Union summit that was meant to agree a Brexit deal. Yet the gap between the two sides remains wide. Theresa May proposed her Chequers plan for future relations only seven weeks ago. That made it wise for Dominic Raab, the Brexit secretary, and Michel Barnier, the European Commission’s Brexit pointman, to agree in Brussels this week to continuous negotiations. It follows a flurry of diplomacy by Mrs May and her foreign secretary, Jeremy Hunt, aimed at averting too firm an EU rejection of the Chequers plan.

A big problem is that Mrs May and her ministers overestimate their negotiating strength. They have been egged on in this by Brexiteers ever since Michael Gove, now environment secretary, claimed in 2016 that, after a Brexit vote, Britain would “hold all the cards”. A glance at the negotiations suggests this was wrong. Britain has slowly but steadily ceded ground to the EU, not the other way round. Three current examples paint a similar picture.

The first concerns growing talk of a no-deal Brexit. Contingency plans from the EU and, this week, from the government confirm how disruptive this would be. They also show Britain suffering the most. Warnings keep mounting against a no-deal exit, from lorry-drivers, NHS trusts, power-suppliers in Northern Ireland and many others. Mr Hunt was right to call the idea a mistake that would be regretted for generations. Yet after criticism he recanted a day later, claiming to have meant that Britain would prosper, but Europe suffer.

This leads to the second diplomatic blunder, using the threat of no deal as a bargaining tool. It is true that neither side wants such a result. Yet Brussels knows it would be far worse for Britain than for the EU. Moreover, European diplomats think the real target of no-deal talk by Mrs May’s ministers is domestic. The government needs to shore up rocky support at home for the Chequers plan by displaying the gory horrors of a no-deal alternative.

The third, related, example is repeated attacks on Brussels for an ideological intransigence that pushes towards a no-deal Brexit. Ministers like the tactic of getting around Mr Barnier and his team by negotiating directly with more pragmatic national governments. The notion that any problem London has with the EU can be solved by appealing to Berlin (and Paris) dies hard among British politicians, although it has seldom worked.

It also misses two other key points. Mr Barnier is operating under negotiating guidelines set by national governments, which he has consulted and kept closely informed throughout the process. And on the EU side he is the person with the most to lose if all goes wrong. A failed negotiation that led to a no-deal Brexit would badly damage Mr Barnier, who harbours hopes of being the next president of the European Commission. That should make him the ally of the British, not their enemy, in finding a mutually acceptable deal.

This does not mean there is no point talking to other heads of government, as Mrs May will do at an informal summit in Salzburg next month. Indeed, if Chequers is to have any chance, she must persuade them to soften Mr Barnier’s guidelines. It is also true that some countries are more inclined to be kind to Britain than others. But her problem is that the two hardest-liners are France and Germany.

The best way to soften them may be to stress the case for close co-operation in non-economic areas such as domestic security and defence. It is surely not to wave around no-deal threats, attack the European Commission and insist loudly on the indelibility of Britain’s red lines.