National Security
Rebuilding Britain's defence capability for a more dangerous and uncertain world.
Make defence one of the central functions of government and progressively rebuild Britain's military capability across nuclear deterrence, conventional forces, cyber resilience and personnel.
What the manifesto commits to
Section VII, Policy 20 establishes a programme to rebuild Britain's defence capability.
Progressively increase defence spending to 5% of GDP within five years.
The earlier 8% figure is not the normal peacetime target. It is retained only as a potential wartime mobilisation level, should national circumstances ever require it.
Why defence is treated as a core function
National security depends on credible deterrence, deployable conventional forces, resilient infrastructure and people who are properly recruited, trained, housed and retained.
This proposal therefore treats defence as a broad national capability rather than a single spending line.
The four priority areas
Nuclear deterrence
- Continuous-at-sea deterrence
- Warhead infrastructure
- Submarines
- Nuclear command and control
Conventional forces
- Ships and aircraft
- Armoured vehicles
- Ammunition and missiles
- Drones and logistics
Cyber
- Offensive cyber capability
- Defensive cyber capability
- Protection of critical infrastructure
Personnel
- Recruitment and retention
- Housing
- Pay
- Training
- Support for veterans
A five-year defence trajectory
The working manifesto sets out an illustrative path for reaching the 5% peacetime commitment. The starting point is an original modelling assumption, not a newly verified current-spending figure.
| Defence trajectory | Illustrative spending |
|---|---|
| Original assumed starting point | ~2.5% GDP |
| Year 1 | 3.0% |
| Year 2 | 3.5% |
| Year 3 | 4.0% |
| Year 4 | 4.5% |
| Year 5 | 5.0% |
Scale and fiscal significance
Reaching 5% of GDP would be a very substantial increase and one of the manifesto's largest fiscal commitments.
The trajectory is illustrative. Detailed implementation would need to test affordability, sequencing, industrial capacity and the outcomes delivered for each additional pound.
The details still need testing
The working master identifies the spending destination, the five-year ambition and the broad capability priorities.
It does not yet provide a complete procurement programme, independently certified costing or detailed implementation architecture. Those elements should be developed through evidence and scrutiny.
Questions for scrutiny
- What fiscal pathway could reach 5% of GDP without weakening essential public services or economic stability?
- Which capability gaps should be addressed first, and which measurable outcomes should determine whether additional spending is working?
- How should Britain balance nuclear deterrence, conventional readiness, cyber resilience and support for personnel?
- What procurement reforms would reduce delay, waste, cost overruns and dependence on fragile supply chains?
- How should investment strengthen Britain's domestic defence industry, skills base and sovereign manufacturing capacity?
- What recruitment, retention, housing and pay reforms are needed to support serving personnel and veterans?
- Which safeguards should govern offensive cyber capability and the protection of civilian critical infrastructure?
- Under what clearly defined circumstances could a wartime mobilisation level above the 5% peacetime commitment be justified?
Make defence a central function of government. Progressively increase spending to 5% of GDP within five years, focus investment on the nuclear deterrent, conventional forces, cyber capability and personnel, and retain 8% only as a potential wartime mobilisation level — not a normal peacetime target.