EU diplomat warns against '˜insane' cliff-edge Brexit

Sir Ivan Rogers, who quit in January after telling Theresa May that Brussels diplomats thought it might take 10 years to reach a deal, said the EU has a strong incentive to reach an agreement with Britain.

But he warned that its “legalistic” nature could mean that if the Prime Minister follows through on her threat to quit with no agreement rather than accept a bad deal, “everything falls away”.

Sir Ivan said the consequences of the UK falling off the “cliff edge” into a “legal void”, relying on World Trade Organisation rules, would be “nuts” and both parties need to strike a deal.

Appearing before the Commons Brexit Select Committee, he pointed out that Bank of England governor Mark Carney has said such a scenario could pose a risk to eurozone stability.

Sir Ivan said: “There are other consequences in other sectors which would make it an insane thing to do.”

He added: “This (the EU) is a very legalistic body that we are dealing with and they will say you have transformed yourselves overnight from having been a member of this body to a third country outside the body and in the absence of a new legal agreement everything falls away.

“We all know that that’s nuts in the real world, because why would you want to stop UK planes flying into European airports.

“We know that this is insanity ... we know that stopping carcasses and consignments and saying ‘your slaughterhouses are no longer approved’ - we may know that that is a nonsense in the real world. Sadly, that does not stop it necessarily happening.”

On the EU he said: “That is economically damaging for them, they will obviously assert and insist that it’s less economically damaging, but ... we will be, when outside the European Union, their single biggest trading partner, so why would you want an abrupt stoppage of flows and goods and services?

“Unless you’re nuts you ought to want to do that, so there is an incentive on them to agree as well.”

Sir Ivan also warned that the EU is unlikely to agree specific deals for industries like car manufacturing, and that the issue of money is likely to get “gory”.