The performance of the electoral system

Section 1: Context

The House of Commons is elected by the First Past the Post (FPTP) electoral system. Whatever its imperfections, FPTP is supposed to have one crucial advantage over its proportional rivals: it generally produces single-party majorities, which, its supporters say, help deliver (to coin a phrase) strong and stable leadership.

This election has not strengthened the case against FPTP. But the result does weaken the positive case for FPTP. That case is based largely on the claim to foster single-party majority government, which the system has again failed to deliver. If FPTP continues to produce minority governments, it will become less obvious why its disadvantages ought to be tolerated.

Clearly, that did not happen this time. Indeed, this was the second election in three that failed to perform as FPTP’s backers expect. The decline of the UK’s traditional two-party system since the 1970s has made such outcomes more likely. Multipartism weakened in this election but did not disappear: the minor parties still hold more seats than at any post-war election before 1997. Unless things change dramatically, results such as this may become fairly normal.

Does that mean that this election result has strengthened the case for electoral reform? Perhaps, but we should not be too hasty.

FPTP’s biggest flaw is generally seen as its failure to translate votes for different parties proportionally into seats. In 2015, for example, UKIP famously secured just one seat despite receiving more than an eighth of all votes. By the standard measure (the so-called Gallagher index), however, the 2017 election was the least disproportional since 1955 and by far the least disproportional since 1974. The reduction mostly reflects the shift back towards two-party politics: FPTP is much more likely to distribute seats in rough proportion to votes if those votes are overwhelmingly cast for only two parties.

At the same time, this proportionality may have been achieved at a cost: at least some voters clearly felt forced by FPTP into backing one of the two main parties to avoid ‘wasting’ their votes. Such tactical imperatives limit voters’ ability to express their true preferences. But it is too early to say confidently whether levels of tactical voting were unusually high or low this time.

Another concern about FPTP is that it can give majority power to a party with only minority support among voters. In 2005, Labour won a clear majority on only 35.2 per cent of the votes cast (or, given low turnout, just 21.5 percent of the eligible electorate). This time, however, the Conservatives won 42.4 of the vote and 29.1 of the eligible electorate. In both cases, these are the highest figures for one party this century.

Supporters of FPTP praise it for holding MPs accountable to local voters. FPTP’s detractors, by contrast, point out that this often fails to work in practice: in safe seats, the candidate of the majority party will almost inevitably win. The proportion of marginal seats has tended to fall somewhat over time, favouring the anti-FPTP side of this debate. This time, however, numbers of marginals rose: 14.9 per cent of seats now have margins below 5 per cent – the highest figure since October 1974 – and 26.0 per cent have margins below 10 per cent. There are, of course, still some extremely safe seats: thirty-five have margins above 50 percentage points. But the problem has shrunk.

FPTPs’ critics also point towards its poor record in promoting representation of society in all its diversity. Each party has only one candidate in each constituency and will therefore seek the candidate who it believes will appeal to most voters. Given stereotypes and expectations, that is most likely, on the traditional view, to be a white male. Assessing the system’s 2017 performance on this criterion requires some nuance. The number of women MPs – 208 out of 650 – is the highest ever, and, at 32 per cent, the proportion is ahead of the European average. But we remain behind most of the long-standing democracies of north west Europe that should be our comparators. The House of Commons also still lags the Scottish Parliament, Welsh Assembly, and UK delegation to the European Parliament, all of which use more proportional systems, though it is marginally ahead of the Northern Ireland Assembly. There are, meanwhile, 52 BME MPs and, according to Andrew Reynolds of the University of North Carolina, 45 out LGBT MPs – a world record share. Whether FPTP is still holding back social representation in the UK therefore looks unclear.

Where does this leave us? The problems generally associated with FPTP have in fact been relatively mild in this election: disproportionality is unusually low, the government’s popular support base is larger than in other recent elections, society is better represented, and fewer MPs have safe seats. This election has not strengthened the case against FPTP.

But the result does weaken the positive case for FPTP. That case is based largely on the claim to foster single-party majority government, which the system has again failed to deliver. If FPTP continues to produce minority governments, it will become less obvious why its disadvantages ought to be tolerated.