London Mayor Boris Johnson on Sunday called for Britain to leave the European Union.
The Conservative leader’s decision, which he said he came to “after a huge amount of heartache,” holds heavy weight as the country is set to vote in June on whether Britain should stay in the E.U., the Washington Post reports.
“I don’t think there is anything else I can do,” Johnson said. “I will be advocating Vote Leave because I want a better deal for the people of this country, to save them money and take back control.”
Leaders are assessing a provisional deal to redefine Britain’s relationship with Brussels. Johnson’s choice goes against that of U.K. Prime Minister David Cameron, who says Britain will be “safer and stronger” within the E.U., according to the BBC.