The 2015 United Kingdom general election is shaping up to be the closest and potentially the biggest headache for markets for decades. The reason? Thanks to the increasing influence of smaller parties, this vote could spell the end of the traditional two-party system that has dominated U.K. politics since World War II.
Since 1945, Brits have only really had one choice when it comes to government: either left-leaning Labour or the more right-wing Conservatives, currently leading a coalition with the smaller Liberal Democrats. But now the likes of the Scottish National Party (SNP) and the U.K. Independence Party (UKIP) could hold the key to who forms the next government.
With both Labour and the Conservatives hovering between 30-35 percent of the vote in a range of polls, it seems unlikely at this point that either will be able to govern alone.
Trade in sterling has already become more volatile than before any election since 2000, as worries about post-election risk intensify.
CNBC takes a look at why every vote counts in the May 7 U.K. general election and which party, or group of parties, could form next government.