The government has set out details of its proposed new security treaty between the UK and the EU after Brexit.
Minsters want the treaty to provide a legal basis for continued security, law enforcement and criminal justice co-operation after the UK’s departure.
They say it aims to maintain operational capabilities between the UK, the EU and its member states.
The plans, published in a government document, are described as a new, “ambitious” model of co-operation.
Whitehall officials said they were “optimistic” they could obtain an agreement, but said if it did not happen, police and security agencies would “find other ways to keep us safe”.
They also said it was possible for the UK to secure an agreement with Europol – the EU intelligence agency – that provides the same benefits as now.
The document rejects the idea of negotiating a number of separate agreements covering each area of law enforcement.
Officials say the new treaty would aim to replicate the provisions of the European Arrest Warrant system, under which suspects can be speedily extradited between member states, but it would not necessarily mean Britain belonging to the EAW.
The UK has the largest defence budget in the EU and, along with France, is one of only two countries in the bloc with permanent membership of the United Nations Security Council.
In her letter formally triggering Brexit in March, Prime Minister Theresa May warned that failure to reach a Brexit deal would mean “co-operation in the fight against crime and terrorism would be weakened”.