There is a famous scene in the film The Life of Brian in which a man is about to be stoned to death for saying the word “Jehovah”. Realising that he is going to be executed anyway he starts jumping around and shouting “Jehovah! Jehovah!” When the Pharisee, played by John Cleese shouts “you’re only making it worse for yourself!” the man replies that he is going to be stoned to death anyway so he might as well do as he wishes.

This scene sprang to mind when I recently heard Stefaan de Rynck, Michel Barnier’s chief of staff, speak to an audience at my home university, University College London. De Rynck made it clear that the EU would take a very dim view if the UK dragged its feet over implementing its commitments agreed in the Northern Ireland protocol to the UK’s Brexit agreement.

While that should be reassuring to the Irish Government, the problem is that, if what Boris Johnson has been saying is true, it appears the UK is heading for a form of Brexit under which the UK will not agree to follow EU single market rules and is therefore inevitably facing significant restrictions in its access to that single market.

This leaves the EU in the position of the Pharisee in the The Life of Brian telling the man facing stoning that he is making things worse for himself. The main source of the EU’s negotiating power has been the threat of loss of access to the single market for the UK. If the UK is hell-bent on a course of action that makes such a loss of access inevitable, then that threat loses much of its force.

Movement of goods

This is worrying because the Northern Ireland protocol to the Brexit agreement relies heavily on British co-operation in its implementation. While under the protocol, Northern Ireland is effectively part of the EU for the purposes of customs and free movement of goods; it is British officials, not EU officials, who must implement EU rules in these areas in Northern Ireland.

It is British officials, not EU officials, who must implement EU rules in these areas in Northern Ireland

In addition, the detailed rules needed to operate the protocol have yet to be set out and need to be agreed between a “joint committee” of UK-EU representatives.

Indeed, in recent weeks, Johnson has been making somewhat worrying noises. Although it is entirely clear the protocol requires some checks on goods moving between Great Britain and Northern Ireland, the prime minister and his foreign secretary have both been insisting there would be no such checks.

If the British refuse to implement their commitments, the EU can bring the matter to arbitration but the arbitration panel cannot issue directly effective rulings in the way that the European Court of Justice can. It can merely impose a financial penalty or permit the EU to retaliate by refusing to comply with its own obligations under the Brexit agreement.

Brexit did not feature much in the general election campaign. Voters are understandably tired of an issue that has consumed over three years of political debate. Furthermore, the parties are united on the issue and the Government is rightly seen as having succeeded in achieving its main objective of avoiding the imposition of physical infrastructure on the Border.

However, it would be a mistake to think that Ireland’s Brexit problems are at an end. It is not just that there are worries around the EU’s ability to force the UK to live up to its commitments in the Northern Ireland protocol.

Trade barriers

Even if the British fulfil those commitments in good faith, the protocol does not prevent the imposition of significant trade barriers between the Republic and Great Britain. As the Conservative government adamantly refuses to accept the idea of the UK following EU single market rules, significant restrictions on access to the UK market for Irish goods, including agricultural produce, are inevitable.

As the Northern Ireland protocol covers trade in goods but not trade in services, restrictions on selling services between Northern Ireland and the Republic are likely

What is more, as the Northern Ireland protocol covers trade in goods but not trade in services, restrictions on selling services between Northern Ireland and the Republic are also likely.

Northern Ireland is likely to be left in the awkward position of being effectively in the EU for the purposes of goods but outside the EU for the purposes of services. This could be quite difficult economically as EU goods law will often be designed to dovetail with EU services law while Northern Irish services law, coming from the UK, may be quite different.

It has often been said that, under the protocol, Northern Ireland will, in economic terms, have the best of both worlds. That is possible, but it is also possible that it will fall between two stools and will suffer from misalignment between its laws on goods and its laws on services.

There is more to life than Brexit. The Government has successfully avoided the imposition of physical infrastructure on the Border and voters are right to be concerned with issues such as health, housing and the economy more broadly.

However, that should not blind us to the reality that Brexit means that coming down the tracks are both a significant shock to east-west trade and, indeed, new barriers to North-South trade in services. We are not out of the Brexit woods just yet.

Ronan McCrea is professor of constitutional and European law at University College London