In the 1931 U.K. general election, the Conservative Party won 55% percent of the popular vote. From this election on, no single party has won a majority of the votes cast. Indeed, in the eleven elections held since Margaret Thatcher’s first victory in 1979, no party has managed even 45% of the vote.
This is neither surprising nor concerning: unlike the U.S., the U.K. has a multiparty democracy with many regional and national-level factions picking up votes. But what is striking is that nine of these eleven elections have resulted in a single party winning an outright majority in the House of Commons (the two exceptions being David Cameron’s coalition government following his debut 2010 campaign and Theresa May’s minority government after her disastrous 2017 snap poll). From Churchill to Thatcher to Johnson, every single-party majority in the House of Commons has been artificial: the result of electoral geography rather than a proportional representation of voters’ preferences.
The Electoral Context
However, unlike the U.S. Senate, which has shown a significant Republican bias in nearly every election since 1972, the U.K. House of Commons does not have a consistent partisan skew. Rather, the country’s first-past-the-post, single-member district electoral system tends to inflate the power of the winner of the popular vote.
In the above chart, two-party electoral bias refers to the difference between the seat margin in the House of Commons and the popular vote margin, accounting only for the seats and votes won by the Conservatives and Labour. In other words, it represents the percentage points of seats one party gains over the other due to electoral geography, with a positive value representing a pro-Conservative bias and a negative value representing a pro-Labour bias. The color of the data point represents the party that won the popular vote. In the three elections in which Margaret Thatcher was party leader, the Conservatives won the popular vote and enjoyed an electoral advantage, hence having positive values for electoral bias. Conversely, in the three elections in which Tony Blair was party leader, Labour won the popular vote and enjoyed an electoral advantage, hence having negative values for electoral bias.
The House of Commons thus displays a consistent bias not towards a particular political party but towards the existence of outright parliamentary majorities. Not all of this pro-majority bias is created equal: Labour’s electoral advantage under Tony Blair was far greater than the Conservatives under Thatcher, Major, Cameron, May, and Johnson. Regardless, since 1979, the 2010 election was the only contest in which the party that won the popular vote did not have an electoral advantage, with Cameron facing a relatively small two-party disadvantage of around 2.5 percentage points.
Given that the Conservatives have won the plurality of popular support in recent elections, Labour’s present electoral disadvantage seems to follow the trend of the loser of the two-party popular vote being underrepresented in the House of Commons. But Labour had a slight electoral advantage in 2010 despite losing the popular vote by over seven percentage points. The Conservative’s 13.5 percentage advantage in 2019 thus raises a simple question: what led to the loss of Labour’s electoral edge? In a word, Brexit.
The Leave-Remain Divide
On June 23, 2016, the U.K. narrowly voted to leave the European Union, plunging the country and the continent into crisis. The Brexit negotiations dominated British political discourse and parliamentary business until the U.K. finally left the Union in January 2020, but perhaps one of the most important impacts of the referendum has been partisan realignment.
The Leave-Remain divide exposed a new axis of discord among the British electorate. Leave voters tended to be less-educated, white, working-class citizens who were swayed by the anti-immigrant, nativist rhetoric propounded by parties like UKIP. Remain voters, on the other hand, generally consisted of urban professionals with degrees who supported increasing diversity and economic integration with the EU.
Brexit did not create this divide out of thin air: rising ethnic minority populations coupled with Cameron’s failed promise to limit immigration primed the nation for the populist xenophobia and nativism that characterized the Leave campaign. As University of Manchester Professors Maria Sobolewska and Robert Ford argue in their book Brexitland, “The EU Referendum itself was not so much a moment of creation, but rather a moment of awakening: a moment when the social and political processes long underway finally became obvious, and the different groups of voters finally recognized themselves as two distinct and opposed camps.” In other words, the demographic and cultural seeds of the Leave-Remain divide may already have been present in the U.K., but Brexit cleanly classified the population into two oppositional groups.
Brexit established a clear division in the British electorate, and with Brexit remaining prominently in the news due to the protracted negotiation process, the political parties realigned around the Leave-Remain question. The Conservatives made significant gains among Leave voters, earning support from less-educated, working-class voters who had previously formed the bedrock of the Labour coalition. With Boris Johnson, one of Leave’s most prominent campaigners back in 2016, leading the Conservative ticket in 2019, the Conservatives broke through the “red wall”: a series of constituencies in the North Midlands and Northern England with large working-class populations that had previously consistently voted Labour. Meanwhile, relying on the support of urban professionals, Labour has made gains among Remain voters mainly in Greater London.
Brexit was thus a catalyst for partisan realignment around the Leave-Remain divide. As Sobolewska and Ford put it, “the referendum made voters acutely aware of new identity divisions and helped to forge new partisan identities rooted in these divisions.”
To visualize the Brexit realignment, this graph plots the two-party vote margins in the 2019 and 2015 elections among English constituencies sorted by whether the district voted Leave or Remain (Chorley and Buckingham are omitted, as these constituencies elected House of Commons speakers). All constituencies above the black line shifted to become more pro-Conservative in 2019 than in 2015, and all constituencies below the black line shifted to become more pro-Labour. Noticeably, the vast majority of constituencies that became more pro-Conservative over the decade voted Leave, while most Remain districts became more pro-Labour. And every single constituency that flipped from Labour to Conservative between 2015 and 2019 in England (the constituencies in the top left quadrant of the graph) voted Leave.
This graph demonstrates the same dynamic, though with a color scale based on the Leave-Remain margin in the constituency during the referendum: the darker the red, the more solidly pro-Leave the district, and vice-versa for blue. The districts that the Leave campaign won by the largest margin tended to shift the most towards the Conservative Party; the districts that the Remain campaign won by the largest margin tended to shift the most towards the Labour Party; and the closest districts during the referendum tended to remain near the black line, signaling little change between 2015 and 2019.
Finally, this graph sorts the constituencies based on geographic regions in England. Constituencies in the Midlands and Northern England, which feature large working-class populations and include the “red wall” districts, tended to shift towards the Conservative Party. Constituencies in Greater London, which feature large urban professional populations, tended to shift towards the Labour Party. (Regions can be isolated by double-clicking the legend on the right of the graph.)
Labour’s Dilemma
Clearly, the parties have aligned around Brexit, with Labour becoming the party of Remain and the Conservatives the party of Leave. Given that the referendum was very close — less than two percentage points separated the two sides — this realignment would not give either party a significant advantage in a proportional system.
However, within the U.K.’s first-past-the-post system, Leave voters form an extremely electorally efficient voting bloc. Leave won the popular vote in England by only around 53% to 47%, but English constituencies voted Leave by a whopping margin of 373 to 160 seats, roughly a 70% to 30% split. The Brexit referendum was of course decided by popular vote, not by whether Leave or Remain won the most constituencies, thus making the election very close. This is little consolation for Labour, however: given the poor geographic apportionment of Remain voters across the nation’s electoral districts, a coalition built mainly on Remain support likely faces an uphill battle in first-past-the-post elections.
To be sure, Brexit is not the sole cause of Labour’s electoral disadvantage — the present pro-Conservative first emerged in the 2015 election, a year before the referendum. Nonetheless, the Brexit realignment has likely hampered Labour’s prospects of retaking government.
Amid controversies facing the Johnson administration, Labour has recently climbed to a significant lead in the polls. But even if Labour were to match or surpass the Conservatives in the popular vote, the Remain coalition is so concentrated in ridings that Labour is already able to win handily, such as those in central London, that this may not be enough to win a majority or plurality of seats in the House of Commons. For the party to build a sustainable electoral coalition capable of delivering control of government, Labour’s task is clear: it must win back the less-educated, working-class voters that formed the Labour base for decades. Given how ingrained the Leave-Remain identities have already become, this is a tall order for Labour leader Keir Starmer. But, barring electoral reform or dramatic demographic shifts, undoing the Brexit realignment may be necessary if Starmer hopes to take back Number 10.
Image by Ugur Akdemir is licensed under the Unsplash License.
