The UK’s head of counter-terrorism, Neil Basu, said a disorderly no-deal Brexit would block British police from accessing European data on serious criminals, damaging safety and security from October 31st.
As reported by Reuters, Basu, speaking to the Guardian, said that if Britain were to leave the European Union without a deal, the UK’s safety and security would suffer and no amount of planning and preparation could erase the risk.
Police would lose key crime-fighting tools and access to data through the Schengen Information System, as well as passenger name records and the ability to use European arrest warrants.
"It would create an immediate risk that people could come to this country who were serious offenders, either wanted or still serial and serious offenders committing crimes in this country, and we would not know about it," Basu said. "It creates that risk.
"There would still be deep concern. There would be some damage to our safety. I can't put a scale on that."
A no-deal Brexit would mean the return of Interpol alerts and the UK relying on the 1957 European convention on extradition, under which it could take years to return a suspect instead of the current six weeks with the European arrest warrant.
Prime Minister Boris Johnson has said he wants to agree a new deal with Brussels but that Britain will leave the bloc on October 31st without one if necessary and that the country must prepare for the disruption that could follow. In the run up to his UK leadership election, Johnson pledged £1.1 billion to boost police numbers by as many as 20,000 within three years of becoming Prime Minister.
But Basu warned that boosts to police and security service numbers were no longer enough to combat terrorism, saying, “We can make them [the damaging effects] less, but they would be slower systems. Those systems and tools were developed in the EU for very good reason. They were very good. We had just signed up to biometric sharing.”
“In a no deal we’d lose all that. We’d have to renegotiate it.”