Barrister Ben Keith writes for the Times.

The future of policing and criminal justice is in jeopardy.

One of the themes of the Brexit campaign was that exiting the European Union would protect us from terrorists, save us from international criminals and give us “control” of our borders.

Leaving the EU will mean that the UK is no longer a member of the four pillars of pan-European co-operation in criminal justice: the European Arrest Warrant (EAW), Europol, Eurojust and the Schengen border system. The final issue is the jurisdiction of the Court of Justice in Luxembourg (CJEU), which oversees all EU law.

Amber Rudd, the home secretary, has said “it is a priority to ensure that we do remain part of [the EAW]”. During the referendum campaign Theresa May said: “Outside the EU, we would have no access to the European Arrest Warrant.” The Labour Party agrees it is a crucial issue; Sir Keir Starmer made his fifth test of a good Brexit deal about national security and cross-border crime.

In among the rhetoric of continued co-operation with the EU lurks the spectre of a cliff-edge exit producing a legal wasteland, where the UK starts with nothing but history, begging to be let back into the club that we have flounced out of. A hiatus of international law and co-operation would give the edge to criminals to manipulate the system or seek to evade justice.

The idea that we can just opt back in to these measures, as was hinted at by Theresa May during her fraught dinner with Jean-Claude Juncker, belies a complete lack of understanding. For the UK to consider being part of these measures would inevitably mean that the CJEU would have to adjudicate on disagreements — that is after all its purpose. The CJEU is a complex beast — there are few criminal judges and the sheer complexity of trying to adjudicate on 27 interpretations of the same piece of law, between very different legal systems, is not easy. But who else would umpire? Is there an alternative? As yet no one has proposed one.

The Liberal Democrats are similarly concerned. “Keeping Britain safe from dangerous criminals depends on the exchange of information with our European partners. The government has to explain how this can be done without European Court of Justice oversight and common data standards,” said Lord Paddick, the party’s home affairs spokesman.

The other option, more recently espoused by Ms Rudd, is threatening to take all our data from Europol with us when we leave, in the political equivalent of a toddler refusing to share toys. “We are the largest contributor to Europol, so if we left Europol then we would take our information — this is in the legislation — with us,” she said in March. An inauspicious start to negotiations based on mutual trust and co-operation.

The extraordinary thing is that on the issue of co-operation on criminal justice everyone agrees that the UK should try to remain part of the EU network, but no one has any idea of the way forward. Everyone, that is, except Ukip. Jane Collins, a Ukip MEP, tweeted: “The EAW is a travesty of habeas corpus and we must leave it. Enough about security threats — we are a member of five eyes”, conjuring images of a circle of Ukip members chanting habeas corpus like some sort of magic spell. In that dystopian ideal the UK would at least have control of it borders — even if we can’t get anything or anyone in or out of the country.
Ben Keith is a barrister at 5 St Andrews Hill specialising in extradition, immigration, serious fraud, human rights and public law

This article was first published by the Times on 27 May 2017