Britain’s top counter-terrorism officer, Neil Basu says a Brexit deal is “incredibly important for the safety and security of the United Kingdom.
Basu says the deal would guarantee better security and law enforcement agreement than the UK currently has.
Talks between the UK and EU are ongoing, but deadline for a deal is set for December.
The UK left the EU in January, but continues to follow current EU rules until the end of the year while negotiations take place.
Any deal would need to be ratified by the UK and EU parliaments.
The UK had wanted to maintain the current access to shared databases, but the EU says that is not available to none EU members.
Basu says the UK needs to negotiate a security treaty that either retains or improves on the current position.
Meanwhile, prime minister Boris Johnson says he is confident the UK will prosper outside the EU if a post-Brexit trade deal is not agreed with the bloc.