On April 18, British Prime Minister Theresa May called for an early general election, bumping it up from 2020. British voters are set to cast their ballots for the House of Commons' 650 seats on June 8. Brexit will likely dominate the campaign agenda, with many perceiving the election as a vote on May's Brexit leadership.

Though May had previously denied she would call for an early ballot, she argued snap elections were now necessary to counter the opposition's "political game-playing" on the UK's departure from the European Union (EU). For May, who took office after David Cameron resigned in the wake of the Brexit referendum, the vote marks her first attempt to secure a popular mandate.

With the opposition at its weakest position in years, the early election will likely prove a major boon to the Tories, allowing them to comfortably expand their current 17-seat majority in the House of Commons. Overall, the Conservatives have backed May's leadership as she steers the UK towards a hard Brexit, which includes removing the country from the European single market.

Embattled Labour leader Jeremy Corbyn announced his support of May's call for snap elections. He will attempt to position his party as an "effective alternative" to the Tories. Corbyn, a traditional labourist, will campaign on reversing government austerity, nationalizing railways, and investing in wages, all while steering clear of Brexit so as to not alienate the party's pro-leavers.

Analysts predict few election gains for Labour, however, as Corbyn's Old Labour policies and refusal to bend to backbench opposition have split the party. Some Labour MPs challenged his support of snap election, and Labour MP Tom Blenkinsop said he would not stand for re-election due to "irreconcilable differences" with Corbyn.

Tim Farron, current leader of the Liberal Democrats said that, "only the Liberal Democrats can prevent a Conservative majority." After the party's coalition with the Conservatives under Cameron, the Lib Dems were smashed in 2015 national elections, receiving only nine seats. For Farron, the snap election will be a chance for him to significantly build up his party's representation in parliament.

The pro-EU and economically liberal party also used May's announcement to call for a second Brexit referendum. In terms of the June elections, the Lib Dems could benefit from disaffected pro-EU Labour voters and those who seek a "soft Brexit" that would keep the UK in the European single market. According to the party, 1,000 people registered as Lib Dems just after May's announcement.

Like the Lib Dems' Farron, first minister of the Scottish government and Scottish National Party leader Nicola Sturgeon clearly positioned herself against May, describing the Prime Minister's move as a "huge political miscalculation." May and Sturgeon have been a loggerheads over whether or not a second Scottish referendum can go forward before Brexit comes into effect.

The SNP already holds 54 of Scotland's allotted 59 MP seats, leaving little room for gain. However, the party is also unlikely to lose seats as their support has stayed steady. A majority of Scots voted to remain in the EU, meaning that Sturgeon could frame the election as both a call to Downing Street to consider a "soft Brexit" option and to consult the devolved nations in exit negotiations.

Despite being a major player in the campaign to take the UK out of the EU, the UK Independence Party (UKIP) currently has just one seat in parliament. However, the Euroskeptic party still has a support base, and leader Paul Nuttall will seek to paint May as a political opportunist. Yet this will not likely translate into seats as many former UKIP voters have joined May's "hard Brexit" bandwagon.

Other parties currently holding Commons' seats include the Greens (one), Northern Ireland's Democratic Unionist Party (eight) and Sinn Fein (four), as well as Wales' Plaid Cymru (three). The June 8 election date places the UK's national election between that of France (April/May) and Germany (September), meaning parliamentary chambers on both sides of the channel may be in for a shake up.