Psephologists have been warning for decades now that multi-party politics is on the rise in the UK, but for most of the time they have been ignored. Everything changed in 2014 though, and the old guard is struggling to adapt.

Labour and the Conservatives, supported by the London-based media, have long behaved as if they were the only players that counted, even though their share of the vote has declined since 1974 (despite a few spikes upwards in the 1980s) and now stands roughly at 65%. The hung parliament of 2010 changed that focus, but not by very much.

It took the UKIP uprising at the local, European elections and by-elections of 2014 for the political establishment to finally wake up to the messy and unpredictable reality of multiparty politics. Neither Labour nor the Conservatives are expected to win a majority in the 2015 general election and the Liberal Democrats may only just cling to 20 of their 57 seats in parliament.

The arrival of UKIP as a contender has short-changed the three main parties. The Conservatives are the ones who will suffer most. They’ve already lost two seats to UKIP in by-elections and several more electoral losses are expected.

The threat is not as a big for Labour but there are nevertheless tensions in the party because of it. Research from the Fabian Society predicts that Labour may lose five seats to UKIP and has identified 16 seats “that may turn blue” because of UKIP support. The Liberal Democrats have less to fear than either of their main rivals but their MPs in the south west of England are feeling UKIP breathing down their necks.

New threats

But this year has not all been about UKIP. Labour and the Liberal Democrats in particular have other threats to address. The rise of the Green party has caused both to panic. In the latest YouGov poll, the Greens were ahead of the Lib Dems by 2%, attracting 8% of voting intentions.

This surge in popular support may not translate into many seats for the Greens (it is likely to be three more at best), but the party has seen its membership swell by 60% since September, which may cause serious harm to both Labour and the Liberal Democrats. Some studies even suggest that one in eight of those who voted for Nick Clegg’s party in 2010 would now vote for the Green Party.

If the Greens are indeed taking Liberal Democrat voters, it will affect Labour too. In order to win, Labour needs to take a lot of Liberal Democrat votes, so having to compete with the Greens for those defections is less than ideal. If those voters decide to vote for the Greens, Labour may lose several of the seats it needs to obtain a majority.

To make matters worse, Labour faces the threat of the SNP in Scotland. It has been suggested that the SNP’s performance will be one of the biggest uncertainties in the 2015 election but several polls have indicated that it could take between five and 20 seats from Labour. In any case, the SNP is so confident of its popularity that the new leader Nicola Sturgeon has already presented her conditions for forming a coalition government with Labour.

The three main parties are on red alert as newcomers shake up voter intentions. The more visibility they get, the more damage they can do.

As a single party majority looks less and less likely, the Conservatives and Labour explore different options for coalition politics. For the Conservatives, that means thinking about a deal with the Liberal Democrats or the Democratic Unionist Party, and maybe with UKIP. Meanwhile, Labour would focus on the Liberal Democrats as potential coalition partner. But as Nick Clegg is expecting disastrous results for his party, Labour may consider forming a plural left coalition with the SNP, the Greens and the Lib Dems.

The prospect of a multiparty coalition is seen as a step too far by many in the political establishment but most European countries manage multiparty coalitions very well and many finish their four-year terms. There is no reason why a stable country like the UK can’t achieve a similar result.

If anyone tries to argue that the rise of the newcomers is causing dangerous instability, they are probably just trying to push voters back into the two-party system. It may be too late. Multiparty politics cam alive in 2014 and there are no signs of it going away in the year to come.

Eunice Goes does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.