Summary
In the government’s 2025 Budget, the UK’s core military spending is planned to rise to £61.7bn in the current financial year, 2025-26. This is in line with the government’s recent announcement that military spending will hit 2.6% of GDP by 2027, on the way to reaching the new NATO spending targets of 3.5% of GDP on the armed forces, and 1.5% of GDP on other “defence- and security-related” measures. A large fraction of the spending increases are being paid for by huge cuts to the foreign aid budget. In 2025-26, core military spending will be approximately 5.5 times the size of the budget for the Foreign, Commonwealth, and Development Office, responsible for most foreign aid spending. By 2028-29, this figure will rise to 7.5. Meanwhile, funding for action on the climate and nature crises is also being compromised by the continued increase in military spending.
In more depth…
The Labour government’s 2025 Budget largely confirms the huge increases in military spending announced in the Spending Review in June. This spending is planned to reach 2.6% of GDP by 2027, with the aim now being to reach the new NATO target of 3.5% of GDP spent on the armed forces by 2035, with a further 1.5% of GDP to be spent on other “defence- and security-related” measures.
The Budget revealed that, for the current financial year, 2025-26, core military expenditure will be £61.7bn. This is £500 million less than projected in the summer, which is the only significant change to the spending profile announced then. This means that annual core military spending is planned to rise by £13.3bn over a five-year period – well above inflation – as shown in Tables 1a&b.
Table 1a. Annual core military spending for 2023-29 as stated in Budget 2025
| £bn(current prices) | 2024-25 | 2025-26 | 2026-27 | 2027-28 | 2028-29 |
| Ministry of Defence budgets | 60.2 | 61.7 | 65.5 | 71.0 | 73.5 |
Table 1b. Core military spending: headline figures for period 2024-25 to 2028-29
| Total over 5y | £331.9bn |
| Increase in annual spending over 5y | £13.3bn |
| % increase over 5y | 22% |
The UK was the sixth largest military spender in the world in 2024 – and its position may rise as this spending is rolled out.
The planned increase in military spending is earmarked for numerous technology programmes including, especially: nuclear warheads; autonomous systems (including armed drones and artificial intelligence); directed energy weapons (including laser weapons); munitions; and military infrastructure. With the programme to renew Britain’s nuclear weapons system running considerably over-budget, it is likely that much of the extra money will be used plug this major funding gap.
The Budget confirms that much of the increase in military spending will be paid for by huge cuts to the foreign aid budget (known as ‘Official Development Assistance’ or ODA). This has been widely condemned and was discussed in a previous GCOMS-UK briefing. Here we provide updated figures illustrating how the funding gap is growing, by comparing the ratio of core military spending to spending by the Foreign, Commonwealth and Development Office (FCDO) which is responsible for most ODA spending. As shown in Table 2, core military spending will rise from 5.5 times the size of the FCDO budget this year to 7.5 times in 2028-29.
Table 2 also shows how military spending is growing relevant to government spending for tackling climate change and protecting nature, via comparisons with the budgets of the departments responsible for these areas.
Table 2. Ratio of core military spending to departmental budgets related to overseas aid, climate change, and protecting nature
| 2025-26 | 2028-29 | |
| Foreign, Commonwealth, and Development Office (FCDO) | 5.5 | 7.5 |
| Department for Energy Security and Net Zero (DESNZ) | 4.6 | 5.6 |
| Department for Environment, Food and Rural Affairs (DEFRA) | 8.1 | 9.8 |
With limited and uneven progress being seen in efforts to achieve the UN Sustainable Development Goals – including action on international poverty, climate change, and nature protection – this is especially unjust.
Indeed, regarding the budget for climate action, the situation is even worse than the headline figures indicate. Currently, over one-third of the budget for DESNZ is spent on managing the radioactive waste legacy of past nuclear technology programmes – a very high level – so is not being used to reduce greenhouse gas emissions. Furthermore, a large fraction of remaining spending is being directed towards new nuclear power – which is especially expensive, slow, and being prioritised largely because of its potential value to the military.
One final point – the core figures do not include some other areas of military spending, in particular, veterans’ pensions, which are not directly related to current government policies on the armed forces. The Budget 2025 documents stated that this total will be £90bn in 2026-27 – over £28bn more than the core spending.
In summary, the 2025 Budget has confirmed that the government is prioritising very high levels of military spending at the expense of the world’s poorest and most vulnerable, as well as urgent action to tackle the pressing climate and nature crises.
Dr Stuart Parkinson is a member of the Steering Group of GCOMS-UK, and Executive Director of Scientists for Global Responsibility.
References
1 HM Treasury (2025a). Budget 2025. https://www.gov.uk/government/publications/budget-2025-document
2 HM Treasury (2025b). Spending Review 2025. https://www.gov.uk/government/publications/spending-
review-2025-document
3 p.43 of HM Treasury (2025a). Op. cit.
4 NATO (2025). Defence expenditures and NATO’s 5% commitment. June. https://www.nato.int/en/what-we-
do/introduction-to-nato/defence-expenditures-and-natos-5-commitment
5 Core military spending is expenditure by the Ministry of Defence under its ‘resource’ and ‘capital’ budgets. It
excludes certain other military budget lines as discussed in the main text.
6 All figures in this briefing are calculated from those on pp.141-2 of HM Treasury (2025a) – except where
otherwise indicated.
7 Calculated based on a comparison of figures on pp.141-142 of HM Treasury (2025a) Op. cit. and p.44 of HM
Treasury (2025b). Op. cit.
8 pp.141-142 of: HM Treasury (2025a). Op. cit.
9 ‘Current prices’ means that there has been no adjustment for inflation.
10 SIPRI (2025). Trends in World Military Expenditure, 2024. April.
https://www.sipri.org/publications/2025/sipri-fact-sheets/trends-world-military-expenditure-2024
11 pp.17-18 of: HM Treasury (2025b). Op. cit.
12 National Audit Office (2023). Ministry of Defence: The Equipment Plan 2023 to 2033. December.
https://www.nao.org.uk/reports/equipment-plan-2023-to-2033/
13 GCOMS-UK (2025). Spring Statement reveals how huge rises in the military budget hit the most vulnerable
the hardest. March. https://demilitarize.org.uk/spring-statement-reveals-how-huge-rises-in-the-military-
budget-hit-the-most-vulnerable-the-hardest/
14 United Nations Statistics Division (2025). The Sustainable Development Goals Report 2025. July.
https://unstats.un.org/sdgs/report/2025/
15 Porritt J (2025). Ed Miliband’s nuclear nightmares. https://jonathonporritt.com/uk-nuclear-subsidies-desnz-
spending/
16 See, for example, chapter 5 of: Ramana M (2024). Nuclear is not the solution: atomic power in the age of
climate change. Verso books.
17 p.146 of: HM Treasury (2025a). Op. cit.
