BRUSSELS (REUTERS) - The EU will stick to a timetable for preparing to launch Brexit negotiations with Britain, despite Theresa May calling for a snap general election on June 8, a European Union spokesman said on Tuesday (April 18).

"The UK elections do not change our EU27 plans," Preben Aamann, a spokesman for European Council President Donald Tusk, said in a statement after Tusk spoke to Prime Minister May.

Tusk will chair a summit of the other 27 EU national leaders in Brussels on April 29, where he expects them to agree negotiating guidelines he has proposed.

On May 22, Aamann added, governments should agree the directives that EU chief negotiator Michel Barnier needs in order to launch the formal talks.

Barnier has said he expects full negotiations to start in early June, although it remains unclear what the British position on that will now be, given the electoral timetable. May formally triggered a two-year countdown to Brexit on March 29.

Tusk said on Twitter that he had a "good" telephone conversation with May after she called for the election.

In a separate tweet, the former Polish premier likened the surprising twist in the Brexit saga to a movie plot by British master of suspense Alfred Hitchcock: "It was Hitchcock who directed Brexit: first an earthquake and the tension rises."

Tusk was referring to a comment attributed to the late filmmaker that a good film "should start with an earthquake and be followed by rising tension".

May said in her announcement that "there can be no turning back" on Britain's decision to leave the EU, something she herself had campaigned against before last year's referendum.