Late Tuesday, British Prime Minister Theresa May signed a letter formally notifying the European Union that the U.K. is invoking Article 50 of the EU's Lisbon Treaty, beginning the countdown for Britain's exit from the union. Britain's ambassador to the EU will deliver the letter to European Council president Donald Tusk on Wednesday at 12:30 p.m. local time. May's government will then lead divorce negotiations with the EU, and in March 2019, Britain will leave the EU, deal or no deal.
The EU in coming days will come up with draft negotiation guidelines, and EU leaders will meet without May on April 29 to adopt a common negotiating stance. The talks will work to unravel the regulations, laws, and other agreements that have bound Britain and the EU since the U.K. joined the bloc in 1973.