French President Emmanuel Macron said Tuesday, June 13 the door was "always open" for Britain to remain in the EU despite Prime Minister Theresa May saying Brexit talks would begin next week, AFP reports.

The meeting in Paris followed the leaders' remarkably different political fortunes in the past week, which saw Macron's party headed for a massive parliamentary majority, while May lost her slim advantage in the House of Commons.

"Of course the door is always open as long as the negotiations on Brexit have not finished," Macron said in a press conference.

But he stressed that the British people had taken the sovereign decision to leave the 28-member bloc in their referendum a year ago, adding that the beginning of talks would be a milestone.

"Once it (the Brexit process) has started we need to be collectively clear that it's more difficult to reverse course," he said at the Elysee palace.

May stressed that she would stick to her timetable of starting Brexit discussions next week in Brussels, saying the talks were "on course", despite her domestic difficulties.

Her Conservative party lost its majority in a bungled snap election last week which some observers suggested might lead May to abandon her plans for a so-called "hard Brexit".

But she countered: "There's a unity of purpose among people in the UK. It's a unity of purpose having voted to leave the EU that their government gets on with that and makes a success of it."