(VOVworld) - British Prime Minister Theresa May on Tuesday signed the historic letter that will formally trigger the UK’s departure from the European Union.

British Prime Minister Theresa May signs the letter to officially trigger Brexit (Source: AFP/VNA)

The letter will be delivered by Tim Barrow, Britain’s EU ambassador, to EU President Donald Tusk a day later. Formally notifying Mr. Tusk of Britain’s intention to leave the EU by triggering Article 50 of the EU’s Lisbon Treaty, the letter sets the clock ticking on a two-year negotiating period to end the UK’s 44-year membership.

Ms. May on Tuesday evening made separate phone calls to Mr. Tusk, European Commission President Jean-Claude Juncker, and German Chancellor Angela Merkel. They agreed on the importance of entering into negotiations in a constructive and positive spirit, and of ensuring a smooth and orderly exit process.

As Britain begins its break with the EU on Wednesday, Ms. May is scheduled to address Parliament and promise to represent everyone in the UK, including EU citizens, in the negotiations with Brussels.