Theresa May has issued a fresh threat to leave the EU without a trade deal unless the terms of the UK’s future arrangements with Brussels are agreed by next summer.

The Prime Minister said that the point of having an implementation period, due to last around two years after Brexit in March 2019, is that it would allow Britain to “move to the future partnership”.

She suggested that if the UK does not know what that future partnership will look like by the tail end of 2018 then the Government could leave the bloc without the transition deal that she is targeting.

Mrs May’s threat comes after she was the victim of an embarrassing leak relating to a private Brexit dinner she had with Jean-Claude Juncker with a report in the German press claiming the Prime Minister had “begged” the European Commission President for help on the UK’s withdrawal from the bloc.

Mrs May appeared to harden her Brexit approach as she responded to a question in the House of Commons from Iain Duncan Smith, the former work and pensions secretary.

She told MPs: “The point of the implementation period is to put in place the practical changes necessary to move to the future partnership.