Question to the Ministry of Defence:

To ask the Secretary of State for Defence, with reference to the press release entitled New Storm Shadow and missile cooperation to boost jobs as UK and France reboot defence relationship, published on 9 July 2025, how many additional armed forces personnel are needed to fill the 50,000 strong combined joint force.

Detailed planning of the Combined Joint Force (CJF), evolving from the currently existing Combined Joint Expeditionary Force (CJEF), is currently under way with French colleagues following the UK-France declaration announcement. Any future basing will be subject to bilateral agreement between the UK and France and announced in due course when negotiated.

The UK-France Lancaster House 2.0 declaration of 10 July 2025 committed to launch the Combined Joint Force – overhauling the existing Combined Joint Expeditionary Force to refocus it on the Euro-Atlantic and warfighting at scale to deter, placing it on an operational footing for the first time by endeavouring to significantly increase the declared Combined Joint Force (CJF) capacity, up to fivefold, ensuring the ability to plan and command Combined Corps Capability (the highest level of fielded forces in our armies). This Corps can provide the Land component of a broader joint force combining all military functions, as part of NATO or bilaterally. The CJF will facilitate the deployment of a force fully interoperable with NATO and available as the Alliance’s Strategic Reserve; this is a critical step towards the UK and France providing two fully interoperable Strategic Reserve Corps to NATO, enabled by the CJF.

For the CJF Corps, our working assumption is a broadly equal split of force contributions. It will be constituted of UK and French forces held at readiness in their usual national basing arrangements. Existing UK and French exchange officers currently embedded in each other’s structures will act as operational coordination and support for the CJF at times when it is not being actively deployed.

Like the CJEF, the CJF Force will be designed to meet the task at hand. The exact proportion of each nation’s contribution can only be defined with a specific task. The forces required would be selected from the UK and France according to a number of factors, including roles and availability.

We anticipate that the CJF will operate as an integrated force in multi-domain operations and could include, as required, elements from the Maritime, Land, Air, Space and Cyber domains. The CJF is intended to be drawn from existing forces.

The current structure of the CJEF under its Concept of Employment (CONEMP) is that there are no permanently assigned or standing forces, combined headquarters, nor planning teams. The CJEF draws on whichever national high readiness forces are declared as available, including lead elements at very short notice, if required for the operation. These are taken from the UK and France following bilateral agreement as appropriate. No UK Armed Forces units are permanently assigned to form the CJEF.

The CJEF is not intended to be a standing force and thus is not planned to be permanently based anywhere.