With less than two months to the general election on 7 May, it's a good time to look at the state of the campaign, as measured by the opinion polls. We should do this carefully, and avoid focusing on any single poll which could be a misleading outlier.
Electoral Calculus takes a rolling average of opinion polls, using one from each of the major pollsters to reduce bias and increase the sample size. The graph below shows the history of the rolling average so far this year:
The headline result is that Labour is holding steady, with a lead over the Conservatives of about one per cent. It's notable that Labour has not been behind the Conservatives so far this year. Other trends are a small decline in UKIP support and a modest rise in the Greens'. One dog which has so far failed to bark is the pro-government swing which normally benefits incumbent parties as the election approaches. Both the Conservatives and the Liberal Democrats have been mostly flat-lining. The SNP's support in Scotland is not shown on this graph, but it is staying strong at around 44 per cent.
The current position is quite good for Labour. Those vote shares translate into projected Westminster seats as: Con 264, Lab 302, SNP 46, Lib 15, Plaid Cymru 3, SDLP 3, and others 17. This clearly makes Labour the largest party and gives Ed Miliband a strong chance of finding 326 MPs and forming a government. The obvious way to do this is to form a coalition or alliance with the SNP, as has been widely discussed. Other possibilities, even such as a cumbersome five-way Lab+Lib+Plaid+SDLP+Green coalition, do not give a majority with this particular outcome.
If Labour can increase their lead by another one and a half per cent, then they can have a simple Lab/Lib coalition. And if they can increase their lead by two and a half per cent, then they would have an outright majority.
But the Conservatives are still far from victory. They need to reverse Labour's lead and gain a lead over Labour of 7 per cent in order to have a majority. That requires a swing of four per cent of voters, which is not yet materialising. Even for the Conservatives to be the largest party needs a swing of 1.5 per cent, and that merely takes the Tories toward the terra incognita where a Conservative/SNP alliance is the only feasible two-party arrangement, whether the parties welcome that or not.
The current projection is for a Labour minority government. But there is still two months to go.