Guardian projection of polls suggests Conservatives will be largest party but will struggle to beat a Labour-led alliance to form next government

How David Cameron could win the general election but not the keys to No 10

If the UK general election were held today, the Conservatives would get the most seats but David Cameron would struggle to form a government against a coalition led by Ed Miliband, a new Guardian analysis can reveal.



The projection, based on all current polling, suggests the Tories would win 276 seats and Labour 271, both well short of the 326 needed to secure an outright majority. The result would leave both leaders fighting to form a viable government.

The Guardian’s polling projection takes in all published constituency-level, regional and UK-wide polls. The model adjusts these based on factors such as pollsters’ past performance, demographics, when a poll was taken, incumbency and the geographical area sampled. From this it projects each party’s vote share and the numbers of seats it would win. The projection will update every 24 hours between now and polling day on May 7.

The model does not amount to a prediction of what will happen; rather it is a projection based on what the polls are saying right now.

The projection offers an insight into the calculations each of the main party leaders would be making in order to build a coalition to form a government.

Coalition building

Cameron would turn first to his coalition partners, the Liberal Democrats. But today’s numbers suggest Nick Clegg’s party will lose about half of its seats, leaving it with just 27.



Ukip might also be on Cameron’s list, but it is likely to get only between three and six seats. The party is currently on the lower end of this range after a slight dip in the polls over the last five weeks. Completing the pool of potential Tory supply is the Democratic Unionist party (DUP) with its nine seats in Northern Ireland.



Facebook Twitter Pinterest Ukip leader Nigel Farage and his Lib Dem counterpart Nick Clegg are likely candidates to help form a Tory coalition. Reuters Photograph: Reuters

Adding up all the Tories’ realistic sources of support would take Cameron to 315 seats, 11 below the required bar.



Labour, meanwhile, has been stubbornly stuck for some time now on just above 270 seats and today’s figure of 271 leaves Miliband needing 55 seats to form a majority.

The gap between the two main parties is mostly explained by the surge in support for the Scottish National party (SNP) that followed last year’s independence referendum. Anyone doubting the strength of Nicola Sturgeon’s party should consider this: about one in 50 adults in Scotland are now SNP members.



Based on current figures, the SNP would win about 50 seats. Due to the fact that five years ago Labour won 41 of Scotland’s 59 seats, the majority of SNP gains would be at the expense of Miliband’s party.

As things stand, it is difficult to imagine any conversation about forming a stable government that could not include the SNP. So it is significant that the party has clearly stated it will not make any deal with the Conservatives, but is open to talking to Labour.

Labour and the SNP combined are projected to win 322 seats. Miliband would then only need to win over a handful of MPs from Plaid Cymru, the Greens, and possibly the Lib Dems, to take him into Downing Street.



Facebook Twitter Pinterest L to R: The leaders of Plaid Cymru, Leanne Wood, the SNP, Nicola Sturgeon, and the Greens, Natalie Bennett - all potential Labour allies. Photograph: Dan Kitwood/Getty Images

What’s left to fight for?

The evidence suggests that no single party will win an outright majority on 7 May. But with more than two months until voting day, and with the margins between possible government scenarios so tight, there are enough moving parts to yet turn the wheels in favour of either Cameron or Miliband.

At this stage, the most important factor in determining the election outcome is Scotland, and whether Labour can recover votes there. Labour’s win in most Scottish seats in 2010 was so large that even a small movement back to the party would save a significant numbers of those seats. As such, the size of Labour’s loss in Scotland will matter greatly in determining who between Miliband and Cameron emerges atop the largest party in May.

At least two other important trends have emerged since the last election and both will go a long way in determining how many more seats the Tories can shore up before election day.

First, there is the “Green surge”. Over the past two years support for Natalie Bennett’s party has increased more than three-fold, and now hovers around 6.5% in the polls. Despite this growing support, the party is unlikely to win more than the one seat it currently holds. Even one extra seat would come as a surprise. But votes for the Greens come overwhelmingly from Labour, and from Lib Dems otherwise inclined to support Miliband’s party. In constituencies where Labour and the Tories are divided by a couple of points, this could prove decisive.

Second, there’s the rise of Ukip. Five years ago the party won 3% of the vote; it is now on about 15%. Nigel Farage’s party takes votes from both the main parties, however any drop in support would benefit the Tories more than Labour.

The numbers suggest that the electoral impact of both Ukip and the Greens is more about the outcomes they influence than the seats they will win.

Facebook Twitter Pinterest David Cameron (L) and Ed Miliband will be thinking hard about how to pull ahead of each other in the leadup to the election. Photograph: PA

How volatile are the polls?

Looking beyond the top-line projection at how the numbers have evolved over the last few weeks, the Tories are trending upwards while Labour is flat and the extent of its Scotland problem is increasingly clear. Elsewhere, the Lib Dems and Ukip are locked in several extremely close contests with the Conservatives, including in South Thanet where Farage is standing.



Both main parties have enjoyed leads of varying sizes in multiple individual polls over recent weeks. The general trend within UK-wide polls, however, has remained fundamentally stable since November last year with Labour, on average, just ahead of the Tories.

Between now and 7 May national polls will only provide the background music to the real party. This vote is actually 650 elections all rolled up into one, where every seat counts and every seat tells a different story. In a contest so close, a handful of seats going one way or the other will decide who ends up forming the next government.