Britain's May 7 election is on course to be historic, but historic in a confusing and unpredictable way that may not yield a clear winner. In fact, Britain faces the most uncertain election in a generation, with its inscrutable nature being chalked up to a mix of changing demographics, economic worries, the ability of smaller parties to reach new voters, online media, and a general indifference with politics-as-usual. Make no mistake: there is plenty riding on the outcome including the future of Britain's welfare state, whether the UK remains in the European Union (Cameron has promised a 2017 referendum on the matter) and how immigrants are integrated into society. Here is what you need to know to understand why these elections matter for Britain, Europe and the democratic world.

1. Great voter indecision. As many as 40 per cent of British voters are undecided or could switch parties on election day, according to a ComRes survey, published at the end of March. Neither Conservatives nor Labour can expect to garner more than 35 per cent of the votes, leaving both short of a 300-seat majority in a parliament made up of 650 seats. The election is coming at a time when the electorate has changed, too, with an estimated one in 10 voters born abroad. That has elevated the importance of smaller parties such as the Scottish National Party, and the anti-immigrant UK Independence Party, which have vastly different visions for Britain.

2. Many choices. The slew of choices is forcing candidates out of their media comfort zones and into the public's eye in new ways. PM David Cameron has had to compete for voters' attention in the same fora and social media realms as his opponent, Labour leader Ed Miliband. This election cycle has featured a moderated, televised debate between candidates, televised question-and-answer sessions, and debates between opposition parties. Online, viral campaigns supporting candidates have taken on a life of their own.

3. Much noise. Amid the noise, Labour Party leader Ed Miliband has gone through something of a transformation. Long considered the nerdier, less-electable brother of politician David Miliband, in 2010 Ed assumed the leadership of the party after it was defeated by the Conservatives in a general election. Since then, he has been largely written off as a wonk holding the seat of Labour leadership until someone more electable came along. In the intervening years, Britain has seen the rise of the anti-immigrant parties and the punishing aftermath of the financial crisis, leaving voters wary of more economic pain. There is also Labour disquiet over the economic centrist legacy of Tony Blair's New Labour.

4. Miliband reconsidered. The genuine uncertainty about the direction of Britain, along with the decline of the traditional media's kingmaking power has allowed voters to reconsider Ed Miliband for PM even as his image is lampooned. The son of Jewish émigré parents, he has been able to speak to fears of economic inequality in a country that is still the world's 5th largest economy. The clashing visions of Britain's economy have even started to make markets nervous.

5. Forecast: uncertainty. But even if Ed Miliband fares well, a hung parliament - or an election that results in no single outright winner - is expected. That means deal-making between parties with markedly different political agendas would begin. How different? UKIP has ridden a wave of immigration-phobia and anti-European Union sentiment to shake up the political agenda. This is drawing voters away from the Conservative Party in England. The Scottish National Party, which could absorb Labour votes, could seek more powers for Scotland following the failed independence referendum in 2014. The Liberal Democrats are expected to form a coalition with the Conservatives if they win – although the party's leader Nick Clegg has said he's also open to talks with Labour.

6. Small party sway. The end result is that no matter who wins, the big parties are growing more reliant on smaller parties and independently-minded voters. As elsewhere, this tendency is being driven by  internet-powered social media that favours the edges rather than the centre of the political spectrum. Since 2012, in Holland, for example, the country's six largest parties have received between 10 and 16 per cent of the vote each, with no majority forming and no marked swing right or left. Marine Le Pen, the leader of the far-right National Front in France, won nearly 18 per cent of the vote in the 2012 French presidential elections, 10 percentage points behind the mainstream Union for a Popular Movement headed by Nicolas Sarkozy. In both cases, once-dominant parties have seen their advantage whittled away.

7. Conclusion confusion. And if it's a hung parliament, what then? A prime minister can stay in office only as along as it is clear that he can command a majority in parliament. The parties have two weeks to negotiate a working majority before parliament sits again. If a working coalition can't be formed, another election could be called in a few months' time.

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