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Politics Panther · Paper 1 · Political Parties

Divisions in the major parties · Overview

One-page summary · the facts that travel with you to the exam

The single sentence

The British political party system is characterised by two factional, ideologically broad parties that are visibly divided but structurally held together by First Past the Post; the Conservatives' deeper divisions during the Brexit and Reform period explain their 2024 collapse, while Labour's tighter management under Starmer explains its 2024 victory.

Conservative vs Labour divisions, side by side

MeasureConservatives 2016-2024Labour 2015-2024
Leaders in office5 PMs in 8 years (Cameron, May, Johnson, Truss, Sunak)3 leaders in 9 years (Miliband, Corbyn, Starmer)
MPs whip-removed21 in September 2019Corbyn (Oct 2020); 7 over welfare (July 2024)
Defections forming new partyNone (Reform UK existed already)7 MPs to Independent Group / Change UK (Feb 2019)
Largest internal vote against leader59 MPs against Johnson (June 2022); 230-vote government defeat (Jan 2019)172 PLP MPs against Corbyn (June 2016, advisory)
Cabinet resignation cascadeOver 50 ministers in 48 hours (July 2022)None comparable
Election resultWorst in party history (121 seats, 12 Cabinet ministers lost)411 seats on 33.8% (lowest winning vote share since 1922)

The ten facts you should be able to deploy

5 PMs in 8 yearsCameron - May - Johnson - Truss - Sunak (2016 to 2024). Previous five-PM stretch: 22 years.
21 expulsions Sept 2019Tory rebels lost the whip including Ken Clarke, Nicholas Soames, Philip Hammond, David Gauke.
230 votes (Jan 2019)The largest government defeat in modern British history. May's withdrawal agreement.
49 daysTruss's premiership (Sept 6 to Oct 25 2022). Mini-budget on 23 September triggered the financial crisis.
14.3% / 5 seatsReform UK at the 2024 election. Third-highest non-Lab-Con vote share since 1945.
12 Cabinet ministers lostAt the 2024 election. Worst Conservative result in party history.
7 MPs to Independent GroupFebruary 2019 (Berger, Umunna, Gapes among them). Cited antisemitism and Brexit positioning.
29 October 2020Corbyn's whip suspended after the EHRC report; whip never restored.
7 MPs whip-removed July 2024For rebelling on the two-child benefit cap (McDonnell, Long-Bailey, Sultana...).
5 Gaza-protest Independents 2024Including Jeremy Corbyn back as an Independent in Islington North.

Three line-of-argument options

Pick the one that matches the question stem; don't try to argue all three at once.

Three mistakes to avoid

Strongest single line for an introduction. "The Conservatives produced five Prime Ministers in eight years between 2016 and 2024, an unprecedented churn that the previous five-PM stretch took twenty-two years to match." This works equally well rephrased for whichever LoA you choose.
Spec hook. 1.2 The role of political parties; 1.2.2 The Conservative Party; 1.2.3 The Labour Party; 1.2.4 The development of a multi-party system.