UK snap election: Five things you need to know

UK Prime Minister Theresa May has called a snap general election for 8 June, taking the country by surprise.

The previous election was in 2015, so another was not due until 2020.

Ms May pledged several times after taking office last year not to call an early election, so this is something of a U-turn.

Why the U-turn?

The prime minister wants a strong mandate in parliament going into what are likely to be fraught negotiations with Europe over Britain's exit from the EU.

Her Conservative party has a relatively slim majority in the House of Commons, won in 2015 under the previous leader David Cameron. But since that election the main opposition Labour party has collapsed in the polls, leaving her in a much stronger position and making an election win significantly more likely.

A victory in June would also hand her a very important personal mandate. Having taken over from Mr Cameron when he resigned mid-term, after losing the Brexit referendum, she has yet to win her own general election.

A former home secretary, Ms May has cultivated an image of iron resolve and dependability.

As fellow top Conservative MPs imploded in the chaos that followed the Brexit referendum, that image helped her emerge from behind as the frontrunner and she eventually became prime minister uncontested.

The 59-year-old served for 17 years in senior positions within the Conservative party before becoming leader, and is said to have harboured ambitions at a young age to be the first female prime minister.

She is the country's second, following Margaret Thatcher.

A snap election needs to be approved by two thirds of MPs in the House of Commons.

The leader of the opposition, Jeremy Corbyn, has already backed the call for an election and so between the two main parties there should be comfortably enough votes to pass the motion.

Ms May said she would put the election to a vote on Wednesday. If it passes, parliament will be dissolved 25 days before the election, on 3 May, for official campaigning to start.

It might seem foolish to call anything a certainty now in politics, but this is probably as close as you'll get.

A raft of Sunday polls in the UK put the Conservatives somewhere between 11 and a massive 21 points ahead of Labour, the largest gap between the parties in the past nine years.

Surveys also suggest that the British public is confident in Ms May's ability to negotiate a good deal from the EU.

The Labour party has collapsed in the polls since the previous general election, plagued by infighting over a divisive leftist leader, Mr Corbyn.

The Brexit vote sowed divisions through public and parliament, and part of the thinking behind this snap election will be to strengthen Ms May's hand at home before negotiations begin in earnest.

Britain has already triggered Article 50 - the formal starting gun on Brexit, and withdrawal from the EU is all but a certainty at this point.

The Labour party has said it supports the outcome of the Brexit referendum, and only the small Liberal Democrat party has expressed a desire to overturn the vote.

But there has been disagreement in parliament over the terms of the exit, and an improved majority will give Ms May more leverage and help to quell arguments among her own MPs.