What's happening?

Theresa May announced her intention to hold an early general election on 8 June 2017, three years ahead of schedule.

"Division in Westminster will risk our ability to make a success of Brexit and it will cause damaging uncertainty and instability to the country," the Conservative UK prime minister said in a statement at Downing Street.

"So we need a general election and we need one now because we have at this moment a one-off chance to get this done while the European Union agrees its negotiating position and before the detailed talks begin."

How can she do that?

Under the Fixed-Term Parliaments Act 2011, general elections are set for every five years, meaning the next is supposed to be in May 2020. But there is a way under the Act for governments to call an early election.

To hold a snap election, the government must table a motion for one in the House of Commons. This motion must then be supported by at least two-thirds of all the MPs in the Commons, meaning 434 out of 650.

May will move a motion on 19 April. If it passes, she will soon ask the Queen to dissolve Parliament and begin the election campaign in the lead-up to 8 June.

A second means under the Act of securing an early election is if a motion of no confidence in the government is passed, and no alternative government is confirmed by the Commons within 14 days.

What if May's motion doesn't pass?

It's possible. Though the Labour leader Jeremy Corbyn has suggested in the past he would support an early election, his MPs have to agree with him. They could still block an early election by voting against the motion or abstaining.

Then what?

Well, she could try again and hope to have convinced enough MPs the second time around. Or she could table a motion of no confidence in her own government, though she may run into the same problem.

There is a third option – she could try to repeal the Fixed-Term Parliaments Act. This would require a new Bill to repeal the 2011 Act, which means it would have to go through the normal course of legislation in Parliament.

This takes time and, though it requires only a smaller simple majority in both the House of Commons and House of Lords to pass, rather than the two-thirds Commons majority for an early election motion, would probably push the date of any early election back.

Looks like we're heading for an early election then.

Almost certainly yes, and probably on 8 June as May wants.