Europe expert Kirsty Hughes writes exclusively for The National on the Brexit scenarios facing the UK - and why the growing crisis could force Nicola Sturgeon into making a decision sooner than she wished on indyref2

THE EU summit that starts in Brussels tomorrow looks set to be another embarrassing occasion for Theresa May. Her last-minute diplomacy aiming to get EU27 leaders to open talks on a trade deal – or even a transition arrangement – during the summit have failed.

At most, the EU27 are expected to agree to start discussing the transition issues among themselves – but not with the UK.

The current impasse is over the so-called divorce bill, so a tough stand-off is not surprising: EU rows over money are legendary. But lack of progress, even with some headway on EU citizens’ rights and on the intractable issue of the Ireland/Northern Ireland border, means no start yet to UK-EU27 trade and transition talks.

This may change in the next two months – the EU27 have long pencilled in their mid-December summit as the possible moment to move to talking trade. But whether the splits in May’s Cabinet will allow much movement on the bill before then is an open question.

Another key question is what the UK Government’s position on a “deep and bespoke” trade deal after Brexit actually is. So far there is no agreed UK position – making the Prime Minister’s insistence on talking trade a little bizarre.

The infighting in the Cabinet between Philip Hammond, Boris Johnson, Michael Gove and others over whether to go for “no deal”, a Canada-style trade deal, or something a bit closer to the EU single market remains intense.

Businesses, universities, the National Health Service, farmers and others are all becoming increasingly alarmed and doing their best to work up contingency plans.

Yet in the midst of the growing uncertainty, there are basically only four main scenarios for where the Brexit talks could end up.

First, the UK could face the intense political and economic chaos of a “no deal” outcome. Secondly, there could be a hard Brexit that covers an exit deal, including a transition period, and an outline of a future free trade deal – though with no guarantee such a free trade deal would be agreed and ratified in the years after Brexit.

Thirdly, there could be a soft Brexit, whether one of staying in the EU’s single market like Norway – or also remaining in the customs union too, as Nicola Sturgeon has proposed. This could lessen any economic harm but leave the UK with no voice or vote on future EU laws and regulations. Fourthly, Brexit could be halted and the UK could stay in the EU after all. There would, though, have to be major shifts in party positions, especially Labour’s, and in public opinion for that to happen.

In the coming months – and for sure by autumn 2018 – one of these scenarios will come about. Under the Tory Government, either a “no deal” scenario or a hard Brexit is most likely. It is inconceivable that May’s Government would support a single market, soft Brexit including free movement of people, let alone reverse Brexit.

So the political and economic path ahead looks unpredictable and unstable. The massive internal re-engineering of UK, and devolved, regulatory frameworks and laws that Brexit requires adds to the political challenges. Whether May can get the EU Withdrawal Bill through – or the migration, trade, customs, agriculture and other bills through – is another question.

Where does this leave Scotland’s Brexit choices? For now, indyref2 remains parked until at least next autumn, when the Brexit deal should be clear (if there is going to be a deal). But if Brexit politics take a more rapid turn, then tough political choices may face all the parties sooner than that.

If the Brexit talks collapse in early 2018, there would be a major political and economic crisis in the UK as “no deal” started to become reality. Labour’s confused Brexit position would come under intense scrutiny. Jeremy Corybn currently supports a “jobs first” Brexit that is difficult to distinguish from the hard Brexit that a Canada-style trade deal would bring. If Labour did shift to supporting a soft, single market Brexit or argued to halt Brexit in the face of growing chaos, then one of those two scenarios might stand a chance of coming about.

But without a Labour shift, it’s hard to see how a soft or no Brexit might happen.

Perhaps if there was an early General Election and the LibDems and SNP held the balance of power, they could push Corbyn to back a second EU referendum. But would the SNP shift its position on a second EU referendum? And unless Labour backed “remain” again, it’s hard to see how such a referendum would be won.

If, by early 2018, it’s increasingly clear that the UK faces a chaotic “no deal” Brexit or at best a damaging hard Brexit deal, and economic conditions deteriorate further, the SNP may face some tough choices. As the damaging reality of Brexit hits, public opinion in Scotland might shift on independence.

A hard or chaotic Brexit looks both most likely to happen and most likely to put a second independence referendum back on to the agenda.

But if the UK ends up trading with the EU on World Trade Organisation terms – amid political and economic instability and uncertainty – or on the basis of a Canada-style trade deal, then there will for sure be a hard UK-EU27 border.

And if the SNP were arguing at that point for independence in the EU, then Scotland would face a hard border with England. This will not make the pro-independence arguments any easier. And hopes of mirroring any Northern Ireland deal look slight. In a hard Brexit, there is no obvious solution to keeping the Irish border frictionless. If UK politics takes a sharp turn away from Brexit or at least to a soft Brexit, then Scotland – like the rest of the UK – could avoid much of the current growing damage.

And if the UK stayed in the EU, any future independence referendum would not face tough questions on borders or trade, if an independent Scotland were also to be in the EU. But if Brexit is halted, then a quick push to indyref2 would dissipate.

For now, a hard or chaotic Brexit is on the cards. And that may lead to tough political choices for all political parties earlier rather than later in 2018. Those who have argued to keep independence debates separate from Brexit may find that isn’t possible in the coming year.

Kirsty Hughes is Director of the Scottish Centre on European Relations