The 2017 general election was never supposed to end like this. At the start of 2017, Theresa May and the Conservative Party held a commanding 13-point lead over Jeremy Corbyn and Labour. Shortly after Prime Minister May announced the election on 18 April, this lead grew further to 21 points. However, since then the picture has changed radically. Across all polls that included fieldwork in June, the average Conservative Party lead has dropped to 6.4 points while a statistical model by pollster YouGov indicated that Britain might be headed for a hung parliament.
At broad level, the race has not narrowed due to a collapse of support for the centre-right Conservatives – who throughout the campaign have consistently polled above 40% of the national vote. Rather, support for Labour has gathered pace as the party has made gains among a coalition of young voters, those who voted Labour at the last election in 2015 but until now had not swung behind Corbyn, ‘non-voters’ who abstained in 2015, women and former Liberal Democrats. In the polls, Labour’s vote share surged from an average of 27% in January to 36% in the final fortnight in May.
While such a shift in Britain is largely unprecedented, it also directly challenges four unwritten laws about elections and voting. First, it has long been argued that elections are won by parties that are perceived to be the most economically competent. In the aftermath of the financial crash, one big reason why Labour lost at the subsequent general election is that it was no longer perceived as economically competent. This largely remains true today. When voters are asked which party would best manage the economy, Theresa May and the Conservative Party enjoy a 16-point lead over Labour – while this is down from 18 points in January, it is still a considerable lead.
A second unwritten law is that the party leader with the strongest leadership scores tends to win the election, with leadership ratings having been shown to be a good predictor. When voters are asked who would make the best prime minister there are certainly sharp differences across the generations – while Theresa May enjoys a staggering 48-point lead among pensioners, Jeremy Corbyn’s holds a 32-point lead among 18–24 year olds. Nationally, however, it is May who holds a 13-point lead. And while this is down from the 33-point lead she enjoyed in January, it is basically the same as the 14-point lead that David Cameron held over Ed Miliband in 2015, just before he won a surprise majority government.
Third, the party that ‘owns’ the most pressing issues for voters also holds a major advantage. According to polls, the top five issues at the 2017 general election in descending rank order are Brexit, the health service, immigration, the economy and education. The Conservatives own three of these, with big leads on Brexit (+19), immigration (+11) and the economy (+16). While Labour hold big leads on the health service (+16) and education (+12), issues that are generally not as salient. This explains why, in the final days, Theresa May is trying to get the conversation back to Brexit and why – if voters are swayed by this issue – it should favour the Conservatives more than Labour.
Fourth, the performance of parties at preceding local elections have also been shown to be a key indicator. Between 1979 and 2015, the only change of government occurred after the average national equivalent vote share for the incumbent governing party lagged behind the opposition party by at least -14 points (as happened before the 1997 and 2010 elections). But at the local elections in 2016 and 2017 the average national equivalent vote share for the Conservatives was 5 points higher than Labour’s, suggesting that a Conservative win is likely.
The polls, of course, could all be wrong. But that seems unlikely given that different polling firms are using different methods and so inevitably some of them should be close to the actual result on 8 June. Also, even polls that give Theresa May’s party a lead of only 5 points indicate that she is still heading for a majority of around 20, which is three seats more than her current working majority of 17. Forecasters are more bullish, with estimates of the size of Conservative majority ranging between 20 and 109. Jeremy Corbyn and Labour have already overthrown the idea that election campaigns don’t make much of a difference but whether they can overthrow older and more firmly established laws in politics remains to be seen.
To comment on this article, please contact Chatham House Feedback