For Theresa May, talking about Brexit at European summits is a little akin to a defendant addressing a courtroom jury.

She speaks; they listen. They don’t ask questions; they don’t respond. She leaves the room; they form their positions without her.

And so it was last night at the historic Felsenreitschule theatre in Salzburg when Mrs May addressed her 27 European counterparts over dinner at a critical juncture in the negotiations.

Michel Barnier, centre, visiting the Irish border, the future of which is the most critical issue for Theresa May to resolve Clodagh Kilcoyne/Reuters

So what does Mrs May want from the summit; what can she realistically expect to achieve and what is the Salzburg meeting’s significance within the broader context of the negotiations and potential Brexit deal?

Why is the Salzburg summit important?

In its simplest terms because time is running out and Salzburg represents one of…