Live: Theresa May calls for snap General Election on June 8

• Video report by ITV News' Europe Editor James Mates

The Prime Minister called for an early general election on Tuesday just weeks after starting the formal process of Britain leaving the EU, causing exasperation amongst some EU leaders.

ITV News' Europe Editor James Mates says the impact of the announcement will result in split reactions, welcomed by business owners but criticised as wasting Brexit negotiating time by others.

It would be the "electoral upset of all time" if Theresa May did not win a proposed General Election, according to ITV News Political Editor Robert Peston.

He told ITV News at Ten that the question would be how big the Conservative majority will be, adding that many Labour MPs do not have confidence in leader Jeremy Corbyn.

But Peston added that Brexit would trump every other issue during the campaign and people would vote for whoever they think will deliver the best Brexit, something that could affect Mrs May's chances.

• Video report by ITV News Political Correspondent Emily Morgan

An impending Brexit and issues surrounding concerns over social care, health care and education could all be influencing factors when it comes to an early election vote.

According to Conservative MP Iain Duncan Smith the PM has called for a snap election as she wants a "strong mandate" to be able to go ahead and make Brexit decisions with the public's backing.

But Labour MP Diane Abbott argued the vote should be "about protecting jobs and living standards" and Lib Dem MP Norman Lamb said "there has to be a focus on the future of our public services" as Britain goes to the polls.

Election analysts are divided over how the election will divide voters.

Colin Rallings, from Plymouth University and our ITV News Election Analyst, said the only way the Conservatives can increase their majority is by winning seats from Labour.

He said: "It's the Conservative / Labour battle that is key to the outcome of the election."

Professor Jane Green, of the University of Manchester, said: "This election has the potential to be a game-changer in terms of the dividing line of British politics.... we know that left right voting is becoming less common."

She said the electorate has "become more volatile" and "you have the potential for a big shock election".

Former Prime Minister Tony Blair has called on Britons to use the opportunity of a snap election to vote for MPs who have an "open mind" when it comes to Brexit.

Warning that current Prime Minister Theresa May could be using the vote to attempt to win herself a "mandate for Brexit Means Brexit aka Brexit At Any Cost", he urged voters consider whether their chosen candidates would be "prepared to hold the Government properly to account in the interests of the country".

Writing on his website, he said: "The political situation the country faces is unprecedented and dangerous. We risk a Parliament which is lop-sided in its make-up; which has a big Tory majority."

Stating that during Brexit talks it would be more important than ever to have elected MPs who were asking the right questions to ensure a good deal for Britain, Mr Blair added: "This requires the electorate in every constituency to know where the candidates stand; and the mobilisation of the thousands in each constituency to make it clear that for them this issue counts when it comes to their vote.

"To be clear: I am not urging tactical voting or some anti-Tory alliance; I am urging that, as part of this election campaign, we create the capacity for the people to know exactly what the choices are; and elect as many MPs as possible with an open mind on this issue who are prepared to vote according to the quality of the deal and the interests of the British people."

Prime Minister Theresa May made a surprise U-turn today and called for an early General Election - despite repeatedly ruling it out in the past.

Mrs May's decision raised questions over why she has taken the risk of putting her future in the hands of voters in "a gamble she didn't need to take".

But polls put her popularity ahead of other leaders, leading to suggestions that could be behind the timing of the vote.

ITV News Political Correspondent Libby Wiener reports: