Analysis carried out and published on 18 October 2026. Data covers Prime Minister’s Questions from October 1964 to 27 April 2022 and party leaders’ conference speeches from 1945 to 2018.
This is the second test of the same idea. After the US presidential debates, the question is whether British political language shows the same drift. Britain offers two long records made under very different conditions: Prime Minister’s Questions, where the Prime Minister answers live in the Commons every week, and the leader’s speech to the annual party conference, written in advance and delivered to the faithful.
What I measured
Exactly the same ten metrics as in the US analysis, on equal 1,000-word chunks. For PMQs I scored only the Prime Minister’s own answers, grouped by Prime Minister and Parliament. I removed ritual sentences such as “This morning I had meetings with ministerial colleagues and others”, which appear thousands of times and say nothing. Very long periods were sampled down to 60,000 words, keeping the order of the answers. Wilson’s short 1964–66 and 1974 Parliaments are too thin in the record to score.
Conference speeches are scored as a separate corpus, one speech at a time, so their zero is the average conference speech rather than the average PMQs answer. The metric definitions are in the US analysis.
What the data shows
Prime Minister’s answers at PMQs, period by period
Complexity index for each Prime Minister in each Parliament, in date order. Bars to the right are above the average of all periods.
Vocabulary against reasoning markers at PMQs
Vocabulary score (variety and rarity of words) against reasoning score (analytic style, qualifiers, causal words, abstraction, concept breadth, minus absolutist words and repeated phrases).
Party leaders’ conference speeches, 1945–2018
Each dot is one leader’s speech to their party conference. Scored the same way, but as a separate corpus, so its zero is the average conference speech.
All PMQs metrics
Raw values per period. Tap a column heading to sort. Rates are per 1,000 words.
Does one metric drive the PMQs result?
Rank correlation between the full index and an index rebuilt without each metric. Values near 1 mean the ranking barely moves.
Four things stand out.
At PMQs the decline is clear, and recent. The index falls with time (a rank correlation of −0.64, which is unlikely to be chance), and every period since Gordon Brown took over in 2007 sits below the 1966–2007 average. The highest scores belong to James Callaghan (1976–79), the last two years of Tony Blair and Margaret Thatcher’s first term. The lowest belong to Theresa May’s first year and Boris Johnson’s first months.
It is not a story about populists. Theresa May, nobody’s idea of a populist, has the lowest score of all. Johnson’s vocabulary is close to average, but his reasoning markers are the weakest of any period. As in the US, the whole stage moved, not one actor on it.
What changed is mostly abstraction and analytic style. Prime Ministers now use plainer, more concrete words and a more conversational structure. The one measure that rose is breadth: each session now covers more topics, in shorter exchanges.
Conference speeches drift much less. Their trend is weak (−0.18). Text polished by speechwriters resists the change, although even here the words have become plainer and less abstract while vocabulary variety rose. Liberal leaders, David Steel above all, wrote the most complex speeches; William Hague’s speeches of 1998–2000 and Ed Miliband’s of 2012–13 the least. Jeremy Corbyn, often described as a populist, scores above the average.
Read with care
- Hansard is an edited record. Hesitations, false starts and repetitions are tidied up, so the repetition measure understates real speech, and older debates were taken down in shorthand.
- PMQs changed format. Since 1997 there is one 30-minute session a week instead of two of 15 minutes, and questions have become longer and more partisan. Answers are shaped by the questions asked.
- The PMQs data ends on 27 April 2022, so Liz Truss, Rishi Sunak and Keir Starmer as Prime Minister are not yet included. Conference speeches end in 2018.
- Scores are relative within each corpus. A UK zero is not a US zero, so compare trends across countries, not levels.
Next
Spain comes next: the State of the Nation debates and the weekly control sessions in the Congreso de los Diputados.
Sources: Hansard PMQs transcripts and leaders’ conference speeches (originally from TheyWorkForYou and BritishPoliticalSpeech.org), as compiled in N. Bailey’s open “scraping-political-speeches” dataset; lexicons and method as in the US analysis.