Here's what to look out for in today’s Brexit talks for signs of whether we're nearing a deal

What is happening today?

Theresa May is flying to Brussels after Prime Minister’s Questions for talks with Donald Tusk, president of the European Council, before she addresses the whole Council, made up of the leaders of the 28 EU member states.

After that, she will leave the 27 other leaders to discuss Brexit over dinner. She will rejoin them tomorrow for a normal session discussing other matters.

Will they agree anything?

There won’t be a deal today. Officials thought they had a deal at the weekend, but May sent Dominic Raab, the Brexit secretary, to tell Michel Barnier, the chief EU negotiator, that the deal was unacceptable to the British government. A bit embarrassing for the British civil servants who thought they had found a form of words that would work.

So are we heading for no-deal Brexit?

We may be, but it is not hopeless yet. The betting markets put the chance of a no-deal outcome at 46 per cent. The EU side now says a no-deal Brexit is more likely, but May says she is still confident that she will get a deal. Certainly, that officials briefly thought they had bridged the gap suggests that the gap may indeed be bridgeable.

The negotiations are still going on, and they will eventually have to be decided by the leaders rather than officials, so May’s discussions this evening are important.

Aren’t we running out of time?

Yes. It now looks as if there will not be a special meeting of EU leaders in November, which had been pencilled in to sign off on a deal to be agreed in principle today. If there is a deal, it may now have to be sealed at the regular summit meeting on 13-14 December.

If that doesn’t happen, EU leaders really would be up against it. I’m told that the absolute deadline, to give the European Parliament time to ratify a deal, would be a special summit in mid-January.

So what is the sticking point?

It is known as the “Irish backstop”. This was an agreement reached between the EU and the UK in December, by which they undertook to keep the Irish border open – and also to avoid new barriers between Northern Ireland and the rest of the UK.

For 10 months, the EU and the UK have been unable to agree how to put these undertakings into effect.

Why is that so hard?

Because if the UK leaves the EU single market and customs union, goods will have to be checked when they arrive in the single market/customs union to make sure they comply with regulations. These checks might be minimised by a trade deal, but that won’t be negotiated until after we have left.

So the question is what happens after the transition period – which would keep trade rules as they are now until the end of 2020 – if there is no trade deal by then (which seems quite likely).

Surely they can fix that?

The main part of the solution may be that the UK stays in a customs union for longer. There are two outstanding problems with that. One is that Theresa May is under pressure from her cabinet to put a time limit on what she calls a “temporary customs arrangement”.

The other is that the EU side wants to impose new checks on some goods going between Northern Ireland and the rest of the UK. This goes against what it signed up to in the backstop agreement in December, at the insistence of the DUP, but Michel Barnier insists the checks are needed to protect the single market.

So what new ideas are there?

It seems that Angela Merkel, the German chancellor, is prepared to offer a longer transition period. That might help, in a classic EU can-kicking kind of way, but it doesn’t solve the underlying problem – which is what happens when it ends.

So look out for more on that, on what is said about a possible special summit in November, and on the language about time limiting the temporary customs arrangement.

Isn’t a Canada-style deal the easy alternative?

No. Ignore such suggestions. When Boris Johnson says the EU says that a Canada-type trade deal is acceptable, he ignores the EU’s condition, which is that Northern Ireland – and not the rest of the UK – must stay in the single market and customs union. This is as unacceptable to Johnson as it is to Theresa May.