UK Prime Minister Theresa May calls for general election on June 8 She seeks an electoral mandate as she negotiates Britain's exit from the EU.

 -- In a surprise announcement, U.K. Prime Minister Theresa May called for an early general election on June 8 to seek a strong mandate as she negotiates Britain's exit from the European Union.

"I have just chaired a meeting of the Cabinet, where we agreed that the government should call a general election," May said in brief remarks outside 10 Downing Street on Tuesday. Under Britain's Fixed-Term Parliaments Act, elections are held every five years, but the prime minister may call a snap election if two-thirds of lawmakers vote for it.

She said that since Britons voted to leave the European Union in June, the country had come together but politicians had not. She said the political divisions "risk our ability to make a success of Brexit."

"Britain is leaving the European Union, and there can be no turning back," May said. "Our opponents believe that because the government's majority [in Parliament] is so small, our resolve will weaken and that they can force us to change course. They are wrong."

Opposition leader Jeremy Corbyn of the Labour Party, a veteran politician known for holding strong anti-austerity and anti-war views, responded to the news on social media.

"I welcome the PM's decision to give the British people the chance to vote for a government that will put the interests of the majority first," he said. "We look forward to showing how Labour will stand up for the people of Britain."

Corbyn has survived several challenges since the Brexit referendum last year, including the resignation of his shadow cabinet in June, and has frequently employed social media to rally grass-roots support for his leadership.

May replaced David Cameron as prime minister when he resigned the day after the Brexit vote .

Her Conservative Party holds a 21 percent lead in opinion polls over the Labour Party.

She said that if there is not an election soon, "the negotiations with the European Union will reach their most difficult stage in the run-up to the next scheduled election."

"Division in Westminster will risk our ability to make a success of Brexit, and it will cause damaging uncertainty and instability to the country," she said.

After the announcement, the British pound rose against the dollar, 0.7 percent for the day, to $1.2658, recovering from a 0.4 percent drop an hour earlier as rumors swirled about the statement.

The Associated Press contributed to this report.