Figures produced by NIS for the International Campaign to Abolish Nuclear Weapons (ICAN) show the UK’s spending on nuclear weapons increased to £6.5bn in the 2022/23 financial year. The figures were published in the ICAN report Surge: 2023 Global nuclear weapons spending, which shows an increase in spending by every nuclear weapon state. The UK figure is a 17% increase from the previous year, when the UK spent an estimated £5.5bn.
The figure is based on spending in 2022-23, the last financial year for which complete figures are available. It is derived from an estimate of total spending on the UK Defence Nuclear Enterprise (DNE), with the cost of spending on SSNs (submarines which are nuclear powered but not nuclear armed) subtracted from the total.
From the 2023-24 financial year the government has changed how it accounts for nuclear weapon spending, with DNE spending being accounted for as a separate figure within Ministry of Defence (MOD) accounts. In response to a parliamentary question the MOD said they could not provide a DNE figure for 2022-23. However, in 2021 they stated that DNE spending amounted to around 14% of the total MOD budget in 2021-22. Using this proportion and the total MOD budget for 2022-23, we can estimate that DNE spending in 2022-23 amounted to £7.4bn.
While the MOD would not provide figures for the cost of spending on SSN maintenance and support, it did provide the cost of maintenance and support for all the UK’s submarines during 2022-23: £594m. During the 2022-23 financial year six of the UK’s ten submarines were SSNs, so a proportionate cost for supporting and maintaining SSNs during that year is £356m. Additionally, the MOD was running two projects to build SSNs: the Astute programme, which is nearing its end, and the SSN-AUKUS programme which is in the early stages of designing the replacement for the Astute class. These two programmes cost £384m and £180m respectively in 2022-23. Altogether, these costs give a figure for UK spending on SSNs of £921m in 2022-23.
Subtracting £921m of SSN spending from a total of £7.4bn DNE spending, results in a figure of £6.5bn for spending on nuclear weapons in 2022/23.
Comparison to previous forecasts
In 2019 the NIS report ‘Trouble Ahead: Risks and Rising Costs in the UK Nuclear Weapons Programme’ estimated average annual UK spending on nuclear weapons between 2019 and 2070 to be £3.4bn . This conservative estimate was intended to take account of the fluctuations in cost between peak spending on upgrade programmes and more ‘fallow’ periods. However, it was based on MOD figures which at the time forecast DNE spending in 2022/23 to be £5.1bn. Even allowing for recent above-average rises in inflation, current spending spending on nuclear weapons is considerably higher than was predicted five years ago.
Spending is also likely to increase further in the future. The MOD 2023-2033 Equipment Plan showed substantial spending increases compared to the plan produced the previous year, with the largest increases being in budgets relating to the DNE. Although the spread of those increases across the 10 years of the Equipment Plan was not made public, all indications are that spending will have been higher in 2023-24 and will continue to rise in future years.