Rise of Green party and Ukip and the Facebook generation’s growing influence have killed the old order and all bets are off

Political pundits are hedging their bets as never before. Their crystal balls reveal only a thick fog of uncertainty. They can agree on one thing – that it is impossible to say who will be prime minister after the election in five months’ time. “The 2015 election is the most unpredictable in living memory,” says Robert Ford, co-author of a book about the rise of Ukip, Revolt on the Right. “Past elections have been close but none has featured as many new and uncertain factors with the capacity to exert a decisive impact on the outcome.”

Since the economic crash of 2008, faith in political leaders and those who run our institutions has collapsed across the globe. In Britain, the trend has been exacerbated by political and banking scandals that have deepened public cynicism. Some of the effects can be seen in opinion polls as the election nears, and a new generation of voters, empowered by the internet, reject traditional parties and their ways.

Labour and the Conservatives together now account for little over 60% of support among the voting public. The decline of two-party dominance has been gradual but continues apace, as insurgent forces enter the field and confuse the picture.

David Cameron and the Tories believe they have two strong suits: the economic recovery and the electorate’s inability to visualise Ed Miliband as PM. But these may not prove decisive. Photograph: Getty

At the 1951 election Labour and the Tories won more than 96% of the vote between them. The Liberals scored 2.6% and others 0.3%. Today the landscape is changed beyond recognition as a period of four- or five-party politics comes into view. These days Labour and the Conservatives each struggle to rise above 35% at best.

2014 saw profound shifts in British politics that few predicted and that have left most politicians nervous about their futures. First came the rise of the anti-EU party Ukip under its populist leader Nigel Farage. Having secured only 3% of the vote in the general election of 2010, Ukip – which advocates the UK’s withdrawal from the EU – stormed to victory in the European elections in May, taking 24 seats with a 27.5% vote share, beating Labour and the Tories into second and third places respectively. As the experts said its bubble would then burst, it went on to win two parliamentary byelections, installing Ukip MPs at Westminster for the first time and cementing its place as a new force.

Facebook Twitter Pinterest Nigel Farage’s personal rating has slipped in recent weeks but even if Ukip wins only a handful of seats in May its bigger effect will be to make results in scores of marginal seats all but impossible to call. Photograph: Ray Tang/Rex

Farage’s personal popularity has fallen off in recent weeks but Ukip’s support ends the year at around 15%. Even if it wins only a handful more seats in May, its bigger effect will be to make results in scores of marginal seats all but impossible to call. Conventional wisdom used to have it that Ukip would damage the Tories most. That may still be the case but recent byelections have shown it can hurt Labour and the Liberal Democrats too.

Ford says its effect is impossible to judge but it could be profound. “In one seat, Farage’s party may take votes from the Conservatives and help their local opposition. In the seat next door it may be Labour that falls victim to the local Ukip insurgency. How large, and how decisive, this indirect Ukip effect proves to be, is one of the great unknowns of next year’s election.”

Ed Miliband and Labour will focus on the cost of living and the health service but as yet there is little evidence of the kind of visionary thinking that could inspire a sceptical electorate to install him in Downing Street. Photograph: Carl Court/Getty Images

For Labour, a second and potentially greater danger has arisen north of the border, where the SNP used its campaign in the independence referendum to bolster support in former Labour heartlands, among working-class voters who felt left behind and ignored by Ed Miliband’s Westminster-led operation.

If recent polls are correct, the SNP could win at least 20 seats from Miliband’s party at the general election, establishing itself as the largest Westminster party north of the border, and doing enormous damage to Labour’s hopes of a majority.

Mark Ferguson, editor of the website LabourList, says the party’s chances seemed good in early 2014 but are uncertain now. “For much of this parliament a Labour majority seemed achievable but now there are too many variables to predict that with any confidence. Ed Miliband’s fate – and the country’s – is now largely in the hands of Labour prospective parliamentary candidates in target seats and Scottish Labour’s new leader Jim Murphy.”

A third insurgent force whose rise complicates the picture is the Green party, now up to 6% or more in many polls. Attracting support from young, socially liberal, middle-class professionals, it is a danger not only to Nick Clegg’s party but could also attract support from some former Labour voters who chose the Lib Dems in 2010 and whom Labour hopes to woo back in May. “As with Ukip, their greatest impact on the election result could come from their ability to tip the local balance of power in dozens of seats where they have little chance of winning outright,” says Ford.

Facebook Twitter Pinterest Nick Clegg and the Liberal Democrats have suffered a dramatic slump in support as a result of their role in the coalition and are now barely ahead of the Greens with an average rating of about 8% in the polls. Photograph: Carl Court/Getty Images

The Lib Dems – who wanted to show they could be a party of government but have suffered a dramatic slump in support as a result – are in deep trouble. They are now barely ahead of the Greens and average about 8% in the polls. Even their ability to defend their “fortress seats” is in doubt as Clegg faces a strong challenge from Labour in Sheffield Hallam and Danny Alexander tries to head off the SNP in Inverness, Nairn, Badenoch and Strathspey.

If the insurgent parties suggest a new era of multi-party politics has arrived, the new media – most familiar to three million or so young people who will be eligible to vote for the first time in May 2015 – offer new campaigning tools and new opportunities for political engagement.

Whichever party connects best with the Facebook generation will reap dividends – but no one can judge which that will be. Both Labour and the Tories have employed key figures from Barack Obama’s successful 2012 presidential campaign, in which new media played a key part: Labour has signed up David Axelrod and the Tories Jim Messina.

Neal Lawson, chair of the centre-left thinktank Compass, says the parties’ challenge is to identify with a generation that interacts and thinks differently about what politics is and what politicians should do. “Old 20th-century mechanical politics looks hopelessly out of date in a 21st-century world of social media where people increasingly do things together,” he says. “Think Kodak pictures from the chemist, versus Instagram. The politicians were brought up thinking it’s all about them when everyone else has moved on and are making their world. People look for answers to the problems that define the political crisis, namely growing inequality and climate change, beyond the mainstream parties that will never rule as they once did.”

As for the campaign messages that will dominate, no party has a clear trump card. David Cameron and the Tories believe they have two strong suits: the economic recovery, which they say Labour would endanger, and the electorate’s inability to visualise Miliband as prime minister. Yet these may prove less decisive than they hope.

The economy may be on the mend but the coalition has missed its targets on deficit reduction, despite four years of austerity, and last week the Office for National Statistics said growth had been weaker in 2013 and 2014 than previously thought. And few people say they are feeling much better off, or view the future with great optimism, as further cuts loom. Even Cameron has admitted that red lights are flashing on the global economic dashboard.

Gavin Kelly, director of the independent thinktank the Resolution Foundation, says the election is hard to call partly because the underlying economic arguments that will be central to the campaign are so mixed. “Wages and family incomes will be far below where they were at the last election – a worse outcome then anyone imagined. Yet employment fell by less and has bounced back much more strongly than expected, while disposable incomes look like they will start to rise steadily in 2015,” says Kelly.

“The deficit remains stubbornly large, and the government pledges on it have been broken, yet the political fallout from austerity to date has been much less severe than predicted.

“The economic argument that will rage over the next few months is still wide open as the public appears unlikely to swallow whole any of the main arguments on offer: it’s unconvinced by the case for further deep spending cuts, sceptical of claims about how policy measures will boost living standards and unsure of what the recovery will mean for them.”

Labour, meanwhile, will focus on what it calls the cost-of-living crisis and argue that the Tories would take public services back to the 1930s in an ideologically driven blitz of further cuts. Miliband and his team will also accuse the coalition of leaving the health service disastrously ill-equipped to meet the challenges presented by an ageing population, having indulged in unnecessary, costly and unpopular reforms. But as yet there is little evidence of the kind of visionary thinking that could inspire a sceptical electorate.

Cameron and the chancellor, George Osborne, remain more trusted on the economy than Miliband and Ed Balls, although Labour has enjoyed a mini-surge in the polls since Osborne’s autumn statement this month.

Cameron may be the better public performer and appear more prime ministerial than Miliband but he is still nervous about agreeing to television debates, perhaps because he fears he might lose that potentially decisive advantage as election day nears.

The most likely outcome of election 2015 is another hung parliament and another coalition, with neither the Tories nor Labour winning an overall majority. But with a little over four months to go – and so many influences at work – you won’t find many pundits who are willing to go further than that. Get ready for the most unpredictable election of recent times.