To make Brexit happen, Boris needs to work with the Eurocrats he’s insulted. Fat chance they’ll help him now

Averting this harm should see MPs working boldly across party lines for resolution, yet on both sides of the political spectrum the self-interest of power hungry politicians appears cruelly at the fore

As our prime minister and the no-deal zealots of his cabinet revel in Brexit brinkmanship it is worth recalling the legal realities of what threatens to be our post Halloween world.

Not long ago, an embarrassed Boris Johnson was called out for his apparent reliance on Article 24 of the WTO rules which could govern parts of UK trade should we crash out of the EU on 31 October. His mistake was to brush aside the requirement that the EU is a willing partner in the arrangements that follow. Now, though, weeks of anti-EU bluster and rhetoric have alienated the very people the prime minister would need to happily gather round the table.

And that, as troubling as it is, isn’t even the most worrying part of what we’ll optimistically call the government’s no-deal plan.

Our current EU membership constitutes an exceptionally privileged trading position for the UK, unattainable post-Brexit. In the European Commission, I have witnessed the EU and US representatives holding equivalent fire power at the negotiating table from the platform of comparable trading blocks. The sham now peddled by the government, that the UK alone has credible leverage with the US, is astounding.

Yes it would be brilliant if the UK had the weight of 28 nations together but it simply doesn’t. No amount of self-belief, or liberal use of Latin, can eradicate the reality of the parties positions. A UK-US trade negotiation is the equivalent of sending a weekend 5-aside team on the pitch to play Liverpool. It is no surprise the US experts are warning about the desperation for a future deal. There is nothing to gain and everything to lose for the UK, not least for the future of our farming, manufacturing industries and health service.

If the UK leaves with no deal on 31 October 2019, the scale of potential losses is vast. UK exports in 2018 were valued at a whopping £621bn with almost half going to the EU. To avoid devastating tariffs on goods alone, the UK would require, at a minimum, an Article 24 agreement.

This is because Article 1 of GATT demands non-discrimination between trading partners; so if the UK permitted EU goods to enter tariff free, it would have to do the same for all WTO members. Article 24, allows a potential means around that, providing for the formation of (a) a customs union or (b) a free trade agreement or the adoption of an interim agreement necessary for either (a) or (b), subject to various conditions. However, the threshold issue for using Article 24 is an agreement between WTO members. Accordingly for implementation of Article 24 arrangements there need to be a willingness for the UK and EU to step into negotiations.

A transitional agreement to preserve the status quo is needed to avoid disruption. That transition is currently provided for in the Withdrawal Agreement, which is the final negotiated text for UK departure from the EU.

Without an agreement in place, the stark reality is that the UK is in a very dangerous position. In the event of no-deal, to comply with WTO rules, the EU would have to apply external tariffs to UK imports, which in the case of some products, such as lamb and beef, would be crippling for exporters.

Equally the UK could not offer more favourable tariffs to EU importers than it does to other non-EU countries. Goods, including food supplies, would hit inevitable tariff changes. Given that approximately 30 per cent of UK food imports arrive from the EU (11 per cent from non-EU countries under the terms of trade deals negotiated by the EU), emergency measures are likely to be put in place. There simply isn’t time to hurl ourselves into the arms of a toxic Trump deal. And we haven’t even mentioned the extremely important, and unresolved, issue of the Irish border yet…

The knock-on, sometimes life-threatening, harm no deal will have on the most vulnerable people in the UK would be beyond contemplation for most nations committed to protecting their citizens. Averting this harm should see MPs working boldly across party lines for resolution, yet on both sides of the political spectrum the self-interest of power hungry politicians appears cruelly at the fore.

All indicators show Brexit bringing serious harm to the economy, to international relations and to security. Coupled with a mass call for a final say, the obvious course is to put the question of our departure back to the people.

Felicity Williams is a specialist in public law and human rights at Garden Court Chambers