Britain’s departure from the EU is “an historic moment from which there can be no turning back”, Theresa May has said.
She was speaking after Britain’s EU ambassador formally triggered the two year exit process by handing a letter to EU Council President Donald Tusk.
A sombre-looking Mr Tusk said it was not a “happy day” for him or the EU.
The European Parliament warned security cooperation was not on the table as it fired its opening salvo in what are expected to be tough negotiations.
In her letter to Mr Tusk triggering Article 50 of the Lisbon Treaty, Mrs May said failure to reach a trade deal within the two-year time limit could “weaken” cooperation in the fight against crime and terrorism.
But Guy Verhofstadt, the European Parliament’s chief Brexit negotiator, said he would not accept any attempt to “bargain” between trade and security, adding: “I think the security of our citizens is far too important to start a trade off from one for the other.”
Home Secretary Amber Rudd has said the UK could end intelligence-sharing with Europol, the EU policing agency, if there was no agreement.
But in an interview with the BBC’s Andrew Neil, on BBC One, Mrs May said on security that she “would like to be able to maintain the degree of co-operation on these matters that we have currently”.
Downing Street insisted Mrs May’s comments were not intended as a threat to EU negotiators, saying it was a “simple fact” the existing arrangements would lapse if Britain left the EU without a deal.
But opposition MPs accused her of jeopardising public safety by attempting to use security co-operation as a “bargaining chip” in the forthcoming negotiations.
Article 50 of the Lisbon Treaty gives both sides two years to reach agreement so, unless the UK and the 27 remaining EU member states agree to extend the deadline for talks, the UK will leave on 29 March 2019, a Friday.
At a press conference in Brussels, Donald Tusk held up Mrs May’s letter, saying: “We already miss you.”
In a brief statement, he said it was not “a happy day” for him or for the EU and promised to begin arrangements for the UK’s “orderly withdrawal”.
He said the EU’s aim in negotiations was “damage limitation” and to “minimise costs” for EU citizens, businesses and member states.
In a statement in the Commons, Mrs May said: “Today the government acts on the democratic will of the British people and it acts too on the clear and convincing position of this House.”
