Corruption perceptions index during each prime minister's tenure
Every prime minister since 1991, ranked by how the corruption perceptions index changed from their first day in office. Politare shows what happened during a tenure; it does not claim the office-holder caused it.
| # | Prime minister | In office | Total | Per year | Chart |
|---|---|---|---|---|---|
| 1 | Con Theresa May | 13 Jul 2016 – 24 Jul 2019 | −4.0 points 2016 → 2019 | −1.3 points/yr | |
| 2 | Con Boris Johnson | 24 Jul 2019 – 6 Sep 2022 | −4.0 points 2019 → 2022 | −1.3 points/yr |
Sorted by total, highest first. Every row is indexed to the last count complete before the first day in office ("from" marks a start that had to move because that count had no data, or because the period cut it); Levels are per cent changes, rates are differences in points; "per year" compounds levels and divides rates. Tenures with under 12 months, or under three observations, are left out. points, 0 to 100, higher is cleaner · Transparency International, Corruption Perceptions Index (CPI score): perceived public-sector corruption as business people and country experts rate it, comparable from 2012, the score as TI publishes it with its confidence interval · United Kingdom data · as of Sep 2026.