Far from “getting Brexit done”, the UK faces 12 months of Brexit-for-real. On 1 February, the UK becomes an ex-member of the EU, a “third country” in the jargon of international trade.

Should there be a change of heart, the UK would have to apply for membership all over again, joining a queue which includes Albania, Bosnia and Kosovo. There will be Rejoin campaigners in the UK, but it is hard to see them making any impact for decades, if ever.

All that has been negotiated is the withdrawal agreement, including a no-change transition period of just 11 months. Prime minister Boris Johnson has chosen to forego the possibility of an extension beyond year end, apparently in the belief that the prospect of another cliff edge puts pressure on his EU counterparts.

Formal negotiations will commence in March on what will be the most complex free-trade agreement ever negotiated by the European Union and it could turn difficult very quickly.

The UK has ruled out the kind of close relationship with the customs union and single market which would have kept trade flowing and those decisions could prove costly.

Except of course for Northern Ireland, which could end up retaining its trade access to both Britain and the EU. But the protocol on Northern Ireland, the only trade-related item addressed specifically in the withdrawal agreement, is unfinished business and much remains to be clarified.

Brexit was always going to impose costs on the Republic, but the version now contained in the withdrawal agreement raises new headaches for Northern Ireland

Northern Ireland business representatives are alarmed about barriers to trade between Northern Ireland and Britain, far greater in volume than trade across the land border. This trade will no longer be domestic, since Northern Ireland will no longer be part of the UK customs territory.

Even if 2020 sees a long-term trade deal agreed, with no tariffs and no quotas, there would still be a need for checks at Northern Ireland’s ports on goods coming in from Britain, since they would have arrived in the single market.

Preferential

If the UK strikes a preferential deal with the US on certain goods, US firms will want reassurance that their better market position is not undermined by imports, via Ireland, from the EU. That would mean checks at UK ports on goods entering from Northern Ireland.

Dublin Port has been spending serious money on getting ready for Brexit and it looks as if Belfast, Larne and Cairnryan in Scotland will have to do the same. There will be extra costs for hauliers too. Brexit was always going to impose costs on the Republic, but the version now contained in the withdrawal agreement raises new headaches for Northern Ireland.

The UK is a land bridge to Europe for truckers in the Republic since the direct ferries add time and cost. But a similar problem has been created for Northern Ireland: Northern hauliers use Dublin-Holyhead for traffic with the midlands and south of England, and while they will face no checks on the land border, what happens at Holyhead?

What happens to a Northern Ireland truck mixed in with Republic-origin trucks coming off the direct ferries in France?

There is to be a subcommittee dealing with the implementation of the Northern Ireland protocol attached to the UK-EU joint committee overseeing the new relationship, whatever form it eventually takes. The Irish Government has wisely secured a special role in this subcommittee, which will be busy.

Objectives

Prior to the commencement of the talks in March, both the UK and the EU will have to set out their formal negotiating objectives and this could be the first flashpoint.

The EU has already made it clear that the integrity of the single market will be non-negotiable.

Any third country which wishes to access the single market, as Norway and some others have done, is welcome provided they sign up to the European Economic Area agreement. This means compliance with level-playing-field requirements about product safety, free movement of labour, state aid, environmental protection and many other matters, all overseen by the Commission with ultimate rights of appeal to the European Court.

Logic

All of this has been ruled out by the United Kingdom and there is logic to the Brexiteer position. What point would there be in quitting the EU while bound by its rules and policies, without a vote or a voice? But the political leadership has created a situation where the UK, a large, successful modern economy, will have abandoned membership of the EU, irrevocably, in advance of negotiating a concrete alternative.

The trouble is that many in the UK expect a deal which will retain EU benefits without cost or obligation, best expressed by Boris Johnson himself: “My policy on cake is pro having it and pro eating it.”

This is the negotiating position that the voters have chosen, not a policy but flippant bluster now set in stone. The collision with reality will not be pretty.