The United Kingdom has provided formal notice of its intention to leave the European Union.

The U.K. invoked Article 50 of the Lisbon Treaty on Wednesday, setting up a two-year negotiation period over both the U.K.’s departure and future relationship with the EU. A six-page letter signed by Prime Minister Theresa May was delivered to European Council president Donald Tusk shortly before 12:30 BST.

“The Article 50 process is now underway, and in accordance with the wishes of the British people the United Kingdom is leaving the European Union,” May said in Parliament, after the letter was delivered. “This is an historic moment from which there can be no turning back.”

Tusk spoke before cameras shortly after receiving the letter.

“There is no reason to pretend that this is a happy day, neither in Brussels nor in London,” he said. “After all, most Europeans – including almost half the British voters – wish that we would stay together, not drift apart.”

The U.K. narrowly voted to leave the EU in June 2016. By triggering Article 50, the U.K. has put in motion a series of events as it moves toward a break with the EU in 2019.

Key dates:

  • Today: The U.K. invokes Article 50.
  • March 31, 2017: EU Council President Donald Tusk will present the other 27 EU member states with draft guidelines for Brexit negotiations.
  • April 2017: An EU summit is set to be called for 27 member states to approve guidelines and authorize the EU’s chief Brexit negotiator, Michel Barnier, to begin talks.
  • May 2017: Brexit negotiations likely to begin between the EU and U.K.
  • Fall 2017: The U.K. government will likely introduce the “Great Repeal Bill” to repeal all EU laws and replace them with national British laws
  • September 30, 2018: Barnier’s deadline for finalizing terms of the U.K.’s exit from the EU.
  • March 29, 2019: Two-year deadline for concluding Brexit negotiations under European law protocols.
  • April 2019 (TBD): The U.K.’s exit from the EU, following ratification of Brexit by all other member states.

BAL Analysis: The U.K.’s departure from the EU will mean the end of “free movement” for EU nationals and their non-EU family members, and could well trigger an overhaul of the U.K. immigration landscape for all foreign nationals working in the U.K. More will be known about what any future system will look like as negotiations progress, but the invocation of Article 50, while historic, does not immediately change the status of EU nationals in the U.K. or U.K. nationals in Europe. Free movement is set to continue until the day of Brexit in 2019.

For May, the key objectives in the negotiations will include controlling migration outside of the free movement directive for new arrivals and securing reciprocal rights of U.K. citizens currently in Europe against European citizens currently in the U.K. May is under pressure to confirm the right to remain for the 3.2 million Europeans in the U.K. within the first few months of negotiations, but it remains to be seen if this is possible or politically expedient.

May will also have to grapple with a push for a second independence referendum in Scotland, after the Scottish parliament voted this week in favor of holding a vote on independence at some point in late 2018 or early 2019, once the terms of the Brexit deal are known. Scotland voted to remain in the EU and, at minimum, is seeking a differentiated agreement on free movement.

This alert has been provided by the BAL Global Practice group in the United Kingdom. For additional information, please contact

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