British Prime Minister Theresa May has called for a general election in the UK.

The vote will take place on June 8th if approved by the parliament there.

Mrs May made the call as the Brexit process gets underway, saying: "At this moment of enormous national significance, they should be unity in Westminster, but instead there is division."

Another vote had not been scheduled to take place until 2020 under the UK's five-year fixed-term parliament rules.

Two-thirds of parliament must approve the proposed election, meaning the Conservatives will need opposition support.

MPs will vote Wednesday on Mrs May's request for an election.

Her shock announcement comes less than a month after she invoked Article 50, beginning the formal process for the UK to leave the EU. 

Why Theresa May called, and could win, a British general election

Speaking outside Downing Street, Mrs May said: "Let us put forward our plans for Brexit and our alternative plans for government, and then let the people decide.

"The decision facing the country will be all about leadership. It will be a choice between strong and stable leadership with me as your prime minister, or weak and unstable coalition government led by Jeremy Corbyn [and] propped up by the Liberal Democrats - who want to reopen the divisions of the referendum - and Nicola Sturgeon and the SNP."

She added: "Every vote for the Conservatives will make it harder for opposition politicians who want to stop me from getting the job done."

David Cameron, who resigned as prime minister following the Brexit vote, described his successor's decision as 'brave - and right':

Brave - and right - decision by PM @Theresa_May. My very best wishes to all Conservative candidates. @Conservatives

— David Cameron (@David_Cameron) April 18, 2017

Northern Ireland 'concerns'

A spokesperson for the Taoiseach said: "This is [Mrs May's] prerogative and is now a matter for the House of Commons of the United Kingdom.

"This is about Government make up in Britain, the Brexit decision stands and will have to be negotiated in the process set out."

The spokesperson added that Ireland will "continue to represent our interests on Brexit which have not changed". 

Efforts to form an Executive in the North are continuing following last month's Assembly elections.

Foreign Affairs Minister Charlie Flanagan spoke with Northern Ireland Secretary of State James Brokenshire after the announcement.

Mr Flanagan said: "This announcement does not change the Government's commitment to ensuring the best possible outcome for Ireland in the upcoming Brexit negotiations where we will negotiate from a position of strength as one of the EU 27.

"I am of course concerned about the impact of a UK general election on the ongoing talks' process in Northern Ireland and I conveyed these when I spoke with the Secretary of State for Northern Ireland earlier today.

"The Secretary of State told me that his intention, announced last week, remains unchanged - namely, to bring forward legislation at Westminster in the coming days which will include a provision to allow a Northern Ireland Executive to be formed in early May.

"While this will legislatively facilitate the formation of an executive, I am conscious of the political reality that all of the parties involved in the talks will now be competing in a general election and mind-sets will inevitably shift to campaign mode.

"Nevertheless, it is the firm hope of the Irish Government that the talks’ process can continue and conclude successfully in the coming days."

Sinn Féin's Michelle O'Neill says her party is ready to "contest this election", while DUP leader Arlene Foster said the election "provides the people of Northern Ireland with the opportunity to vote for the union".

European Council President Donald Tusk, meanwhile, said he had a 'good call' with Mrs May about the election.

It was Hitchcock, who directed Brexit: first an earthquake and the tension rises.

— Donald Tusk (@donaldtusk) April 18, 2017

Opposition response

British Labour leader Jeremy Corbyn welcomed Mrs May's announcement, saying it will "give the British people the chance to vote for a government that will put the interests of the majority first".

He said: "Labour will be offering the country an effective alternative to a government that has failed to rebuild the economy, delivered falling living standards and damaging cuts to our schools and NHS."

Liberal Democrat leader Tim Farron said: “This election is your chance to change the direction of our country.

“If you want to avoid a disastrous Hard Brexit; if you want to keep Britain in the Single Market; if you want a Britain that is open, tolerant and united - this is your chance."

UKIP - whose only MP quit the party last month - also welcomed the call for an election:

Every vote for @UKIP in this General Election will be a reminder to the PM that the British people want a clean Brexit with restored borders

— Paul Nuttall (@paulnuttallukip) April 18, 2017

An election would also be seen as a major test for Nicola Sturgeon in Scotland, who has called for a second independence referendum.

In a tweet after Mrs May's announcement, Ms Sturgeon suggested the Conservatives see an opportunity to "force through a hard Brexit".

The Tories see a chance to move the UK to the right, force through a hard Brexit and impose deeper cuts. Let's stand up for Scotland. #GE17

— Nicola Sturgeon (@NicolaSturgeon) April 18, 2017