British Prime Minister Theresa May has started the formal process that will divorce the United Kingdom from the European Union, overturning four decades of integration with its neighbors and shaking the foundations of a block that is facing challenges to its identity and its place in the world.
Britain’s top envoy to the EU, Tim Barrow, hand-delivered a letter to European Council President Donald Tusk formally triggering a two-year countdown to the final split.
“Today the government acts on the democratic will of the British people,” May told lawmakers in the House of Commons. “This is a historic moment from which there can be no turning back. The United Kingdom is leaving the European Union.”
In the letter triggering Article 50, May said both Britain and the EU should work hard to ensure there is a deal.
“We should engage with one another constructively and respectfully, in a spirit of sincere cooperation,” she wrote.
May says it is in the “best interests of both the United Kingdom and the European Union that we should use the forthcoming process to deliver these objectives in a fair and orderly manner, and with as little disruption as possible on each side.”
“We are leaving the European Union but we are not leaving Europe,” she told the House of Commons, adding that Britain wants “to remain committed partners and allies to our friends.”
Tusk tweeted that “after nine months the UK has delivered,” followed by a photo of Barrow handing him the letter in front of British and EU flags in Brussels.
— Donald Tusk (@eucopresident) March 29, 2017
There is “no reason to pretend this is a happy day,” Tusk said during a speech later, emphasizing that the priority now is to minimize costs for EU citizens and member states.
But for Britons who voted 52 to 48 percent to leave the bloc in a referendum nine months ago, it was a time for celebration.
“In my opinion, this is the greatest moment in modern British history,” said Brendan Chilton, general secretary of the pro-Brexit group Labour Leave. “We are finally beginning the process by which we leave the European Union, restore our Parliament and once again become a sovereign nation.”
In a statement Wednesday European Union leaders said “the Union will act as one and preserve its interests. Our first priority will be to minimize the uncertainty caused by the decision of the United Kingdom for our citizens, businesses and member states.”
They said they would “start by focusing on all key arrangements for an orderly withdrawal.”
Manfred Weber, president of the European Parliament’s biggest political bloc said Britain’s decision to leave the US is “a tremendous mistake. It will create a lot of damage for both sides.”
But he said the parliament will respect the choice of British voters to leave and that “the negotiations should follow two steps: first we need to agree on the divorce settlement, then we will talk about the new relationship.”
The loss of a major member is destabilizing for the EU, which is battling to contain a tide of nationalist and populist sentiment and faces unprecedented antipathy from the new resident of the White House.
It is even more tumultuous for Britain. For all the U.K. government’s confident talk of forging a close and friendly new relationship with its neighbors, it cannot be sure what it’s future relationship with the bloc will look like — whether businesses will freely be able to trade, students to study abroad or pensioners to retire with ease in other EU states. Those things have become part of life since the U.K. joined what was then called the European Economic Community in 1973.
The trigger for all the economic and constitutional uncertainty is Article 50, a previously obscure clause of the EU’s Lisbon Treaty that allows a member state to withdraw from the bloc. The two sides now have until March 2019 to agree on a divorce settlement and — if possible — establish a new relationship between Britain, the world’s fifth-largest economy, and the EU, a vast single market stretching over 27 countries and half a billion people.
Brexit Secretary David Davis — the man charged with leading Britain’s side in the talks — has called it “the most complicated negotiation in modern times, maybe the most complicated negotiation of all time.”
Tusk has said that within 48 hours he will respond with a draft negotiating guidelines for the remaining 27 member states to consider. Leaders of those nations will then meet on April 29 to finalize their negotiating platform before instructing the EU’s chief negotiator, French diplomat Michel Barnier.
Then Barnier will sit down with his British counterpart, Davis, who has said the first item on the agenda will probably be: “How we do this?”
The Associated Press contributed to this report.