By Jonathan Lis

Hidden away in the government's latest batch of no-deal preparedness notices this week was the dirty little secret that Brexiters have spent the last two years denying. "With no agreement in place," it reads, "UK and EU licensed airlines would lose the automatic right to operate air services between the UK and the EU.”

Brexit's most tangible disaster and Project Fear's most lurid poster-child is at last being dryly reported in government ink: grounded aircraft.

The first plank of the aviation problem comes from permissions and licensing. Airlines would need to gain approval from the countries in which they operate in order to continue flying there. The government says it "envisages" granting permission for EU airlines, but only "expects" EU countries to reciprocate. That is not a concrete assurance that planes can continue to fly, and the government is powerless to insist they will.

The government also points out that we have air service agreements with 17 countries under the aegis of the EU. These include Canada, Morocco, Switzerland and the United States. It apparently has "confidence" that replacement deals will all be ready to implement by next March. Again, these involve negotiations with third countries and the government is unable to guarantee anything. Even if we do manage to secure flights to those 17 countries, there is no assurance the agreements will be as favourable as they are now. The US has reportedly offered a significantly inferior deal.

The key plank of the no-deal disaster, however, arises not from bilateral permissions but safety certificates.

Currently, the UK is in the European Aviation Safety Agency (EASA), which regulates everything from the safety of the airline to the attestation of a plane's cabin crew. The European Commission has confirmed that, in the event of no deal, the certificates granted by the UK's Civil Aviation Authority to pilots, engineers and cabin crew would no longer be considered valid. Even UK approvals granted to aircraft maintenance firms and aviation training-course providers would cease to have effect in EU territory or for EU aircraft. UK-certified firms wouldn't even be able to continue supplying parts for EU planes.

Effectively, the EU would not recognise any of the UK's aviation safety infrastructure. That spells cataclysm for UK airlines and personnel. And even if some EU airlines were able to continue servicing the UK market, it is unclear they could secure the appropriate insurance to do so. We are looking at the total collapse of the UK's aviation system with its largest partner.

These are just the most pernicious elements. They don't even cover the effects of leaving the EU's aviation market. The government frankly admits, for example, that the UK would be out of the Single European Sky, which harmonises air navigation, and that UK airlines would no longer be able to fly between two EU airports.

You can also forget the possibility of easy alternatives to leave this island. The government has quietly admitted that if we don't manage to re-join the Interbus agreement and the EU doesn't recognise the UK's permits, all coach services could be suspended too.

Brexiters will accuse the EU of parading itself in all its vicious, vindictive ugliness and punishing the UK for having the audacity to leave the club. It is not. The EU is a rules-based, supranational organisation which depends on laws and agreements to function at any level. If it abandoned its legal order it would fall apart. In a no-deal scenario, the UK would become a third party without any ties to Brussels. London would effectively be instructing Brussels to void any pre-existing UK-EU agreements and the EU would be obliged to comply. The hardliners want a 'clean Brexit' and that is what it means.

If the situation facing the country wasn't so bleak, Remainers could perhaps be forgiven some schadenfreude. For two years, Brexiters have poured ridicule and abuse on them for pointing out basic legal facts. They were acting in bad faith, they were lying, they were turbo-charging Project Fear. Brexit secretary Dominic Raab dismissed the prospect of grounded aircraft just a few weeks ago. He now stands humiliated, exposed as either ignorant or lying and in any event woefully out of his depth.

Politicians are not alone. Numerous radio presenters have told me that 'nobody believes planes will stop flying' if there’s a no-deal scenario. And that is of course true, most people do not believe it. The talk of no-deal has only been able to gather such momentum because few conceive that a country as developed as Britain could suddenly stop working. This is Britain, rich and reliable. We instinctively resist believing apocalyptic scenarios because they only happen in other places and to other people. But that is grounded in our lived experience, not legal reality. If you set fire to a country, it will burn. Such comforting exceptionalism is the hardliners' greatest asset and the country's gravest danger.

The Brexiters who do not lie have simply been in denial. The Institute of Economic Affairs, for example, has suggested that the UK could remain part of EASA, or negotiate a "new free trade agreement for aviation only". In other words, mitigate the effects of no-deal by, in fact, having a deal.

Others have talked about 'mini-deals'. It is true that the Commission has mentioned the possibility of a 'bare bones' arrangement, but there are no guarantees of this whatsoever. Michel Barnier has ruled them out and the EU has told the government that aviation agreements between the UK and individual member states are a non-starter. Officials also point out that any matter pertaining to our withdrawal has to be endorsed by the European parliament. An instruction to let planes fly cannot simply be emailed out at 11pm on 28th March.

An aviation agreement would also be predicated on prerequisites of constructive human interaction, like goodwill and trust. If the UK has flounced out of the room after a destructive temper tantrum, they may be in short supply.

Let's face it. The government’s aviation notices have laid bare three fundamental truths about Brexit.

First, 2016 Project Fear was in fact Project Downplay. The potentially catastrophic ramifications for aviation did not feature even tangentially in the referendum campaign. The worst of the so-called scaremongering focused on the loss to our economy and influence from exiting the EU's economic instruments. At no point did Remain even begin to address the next-level seam of disaster emerging from no-deal. Why would it? Leave promised that the EU needed us more than we needed them and that a deal would be swift, easy and painless.

Second, nobody is taking back control of anything in Brexit. That defining Leave slogan has turned out to be a pathetic and monstrous joke. In the context of no-deal, we throw ourselves on the mercy of the EU and beg them to let our planes fly.

The third point is the simplest. Planes will not be grounded. Because we will not leave without a deal. Neither the public nor parliament will allow it. And that means that the prime minister will capitulate. The only question is when.

Jonathan Lis is deputy director of the think-tank British Influence and a pro-EU political writer and commentator. You can follow him on Twitter here.

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