Recent statements on defence spending

There have been several posts on X from official government accounts in recent weeks which have referred to the UK’s plan to ‘increase defence spending to 2.5% of GDP by 2030 – an increase of £75 billion’.

We understand that this claim is based on the Government’s publication Defending Britain and was calculated by assuming, as the publication does, that NATO-qualifying defence spending rises steadily from £64.1 billion or 2.30 per cent of GDP in 2024-25 prior to the recent announcement to £87.1 billion or 2.50 per cent of GDP. On this basis cumulative spending over the six years from 2025-26 to 2030-31 is projected to be £460.9 billion, compared to £384.4 billion if annual spending remained flat in cash terms at £64.1 billion – a difference of £76.5 billion (or £75 billion rounded to the nearest £5 billion).

Cumulating spending increases (or cuts) over several years to derive a large cash figure for presentational purposes does not in general facilitate public understanding of the data in question – the longer the period you choose, the bigger the number you get.

Public understanding of the £75 billion figure will also not have been helped by the choice of counterfactual against which it was calculated – holding defence spending flat in cash terms, which would imply a fall relative to the price level and as a share of GDP and thus in all probability in the quality and quantity of defence services that could be delivered. Under the counterfactual, defence spending would have dropped to 1.85 per cent of GDP in 2030-31, breaching the Government’s commitment to NATO to spend at least 2 per cent of GDP. If the counterfactual were, more plausibly, to hold defence spending at the share of GDP planned for 2024-25 prior to the recent announcement, the proposed cash ‘increase’ would drop from £75 billion to £25 billion.

To ensure transparency and maintain trust in the use of official statistics, one of the key expectations of Intelligent Transparency is that high-profile statistical or quantitative claims are presented in a way that a reasonable person on the street will be able to understand them – or that sufficient context is provided to help them do so. In addition, Intelligent Transparency demands that Departments adopt the same rigour for public statements using data regardless of whether they are descriptive official statistics or forward-looking projections.

The use of the £75 billion falls short of these expectations and we will continue to monitor further use of this statement.