JILL LAWLESS, AP
LONDON (AP) — The United Kingdom filed for divorce from the European Union on Wednesday, overturning four decades of integration with its neighbors, demolishing the notion that EU expansion is inevitable and shaking the foundations of a bloc 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." Prime Minister Theresa May told lawmakers in the House of Commons, adding, "This is an historic moment from which there can be no turning back."
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.
There is "no reason to pretend this is a happy day," Tusk told reporters later, emphasizing that the priority now is to minimize costs for EU citizens and member states.
To Britain, he said: "We already miss you."
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.
Former U.K. Independence Party leader Nigel Farage, who campaigned for years to take Brexit from fringe cause to reality, said Britain had passed "the point of no return."
"I can still, to be honest with you, scarcely believe today has come," he said.
For "remain" campaigners, it was time to fight for a divorce settlement that preserves what they see as key benefits of EU membership, including free trade in goods and services and the right to live and work anywhere in the bloc.
"The phony war is over," said Joe Carberry, co-director of the pro-EU pressure group Open Britain. He said Britain had decided that it would leave the bloc — but "the issue of how we will leave, and the democratic checks and balances along the process of the negotiations, remains unresolved."
May's six-page letter to Tusk was polite and conciliatory, stressing that Britons want to remain "committed partners and allies to our friends across the continent."
She said the two sides should "engage with one another constructively and respectfully, in a spirit of sincere cooperation."
European leaders expressed dismay, with Danish Prime Minister Lars Loekke Rasmussen saying Britain's goodbye to the European Union is "incredibly sad" and he expects "many bumps on the road."
Germany's Foreign Ministry said Britain would remain a "close partner and friend" of the EU, but that "being a close friend is not the same as being part of the family."
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.