The Professor Will See You Now: Options
Illustration by Tracy Worrall
4 min read
Lessons in political science. This week: options
Your starter for 10: what links by-elections over the last 100 or so years in Stockport, South Dorset, Walsall North, City of London & Westminster South, Lambeth Central, Croydon North West, Chesterfield, Newbury, Haltemprice & Howden, and Clacton?
The answer is they have, in date order, held the record for the most candidates standing in a by-election. Stockport in 1920 was a rare example of a by-election where both seats in a multi-member constituency were up for grabs, something that would never happen again before they were abolished in 1948. A full seven candidates stood, setting what was then a record. It took more than 40 years before that was achieved in a single-member constituency, in South Dorset in 1962.
The record stood until Walsall North in 1976 (nine candidates); we then had City of London and Westminster South in 1977 (10), Lambeth Central in 1978 (11), Croydon North West in 1981 (12), Chesterfield in 1984 (17), and Newbury in 1993 (19). We jumped to 26 candidates in Haltemprice & Howden in 2008 and then to the 34 in Clacton.
The general rise in candidacies is well known, from an average of 2.2 per constituency at the 1955 general election to a record 6.9 in 2024. But the rise is even more obvious at by-elections, from 2.7 candidates on average during the 1955 parliament up to 11 between 2019 and 2024. The extra publicity makes by-elections particularly attractive for fringe candidates, both the genuine and those from the Standing at the Back Dressed Stupidly and Looking Stupid Party as seen in Dunny-on-the-Wold.
The consequences are still to be understood. A new piece of research, just out in Party Politics, examines the strategic options the rise in candidates gives voters: the more candidates there are, the more options voters have, although not all candidates matter equally and not all parties gain equally.
Estimates of the amount of tactical voting are often misleading, because most voters don’t have the chance to vote strategically. Imagine you support Labour, who are in second place in your constituency, and your least preferred option, the Conservatives, are in first place; the Lib Dems, who would be your second preference, are in third place. If so, you don’t have a strategic option available.
What this research did was to try to look at the number of tactical options open to voters – and then work out how many of these options were used. To measure whether an individual has strategic choices, you need to know both how they rate the parties and how likely they perceived those parties were to win in their constituency. (Some of these perceptions will be wrong but it only matters whether the voter thinks they have a strategic option.)
Drawing on data from the last four general elections, the research found that 28 per cent of voters had the chance to vote strategically, peaking in 2024 at 36 per cent. So, even with all those candidates, most people still did not have the chance to vote tactically. But of those who had a strategic option, more than a third (39 per cent) cent took it – a figure that rose to more than half (51 per cent) in 2019.
By definition, as the article notes, strategic options tend to be one of the larger parties – “to be a strategic option, a candidate must be viable or at least more viable than the first-choice party”. Hence what matters is not the number of candidates per se but the number of places where their candidacies look plausible; so what has really changed things has been the rise in candidacies by the Greens and Reform UK.
To date, the main beneficiaries of this have been the more established parties. Over those four elections, Labour gained the most (some 55 per cent of all strategic voters), followed by the Tories (23 per cent), and smaller parties lost out; nearly half of all strategic voters in this analysis actually preferred the Greens. But saying that this happened in the last four elections – in which Labour was not in government – is not the same as saying it will continue.
Further reading: E Fieldhouse and J Fisher, From strategic voters to strategic options: Recasting strategic voting for multiparty simple plurality elections, Party Politics (2026)
