More than 10,000 personnel in the UK's armed forces are classified as "not medically deployable," according to figures revealed by Defence Minister Alistair Carns. In a written parliamentary response, Carns detailed that 99,560 service members are fully deployable, while 14,350 have limited deployability and 13,522 are medically undeployable.

The breakdown shows 2,922 medically undeployable personnel in the Royal Navy, 6,879 in the Army, and 3,721 in the Royal Air Force. An MoD spokesperson told reporters that despite these figures, "The vast majority of our service personnel – around 90% – are deployable at any point, with most of the remaining members of our armed forces employed in wider military roles."

Personnel with medical or fitness issues are referred to medical boards for assessment and potential downgrading to allow for recovery and rehabilitation. Deployability status can be temporary or permanent, with some restrictions depending on the nature and location of operations.

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Former Defense Minister James Heappey described the figures as "very arresting" but noted that they include personnel deemed unfit for minor reasons. "I'll bet you that a big chunk of the non-deployable, medically downgraded people are downgraded for dental reasons," Heappey told Times Radio. "And what that tends to mean is that they've not had a dental checkup in the last six months, and so they are automatically declared dentally unfit, and therefore not fully deployable."

Heappey also pointed out that some injuries might prevent deployment during peacetime but would not be a barrier in wartime. "There is a reality about the nature of some of these injuries that mean that they couldn't deploy to go on a discretionary operation today in peacetime, but if war was to come, then they would be absolutely able to go and fight because the needs of the nation would rather trump that rather discretionary take on their medical capacity," he said.

UK defense shortfall

The issue comes as the armed forces face challenges in meeting target personnel numbers. MoD statistics from April 2024 show that all three branches are below target size: the Army by 1%, the Royal Navy and Royal Marines by 5%, and the RAF by 10%. Overall, the Army is short by 5,440 personnel.

Budget constraints further exacerbate these challenges. Research from the House of Commons highlights that while defense spending by Russia, Iran, and China has increased significantly since 2014, UK defense spending has grown by just 14% in the same period. Helen Maguire, the Liberal Democrat defense spokesperson, warned, "With an unreliable partner elected across the Atlantic, it is vitally important for Britain's defenses to be strengthened."

In response to criticisms, the MoD pointed to upcoming financial commitments. "The vast majority of this spending was under the previous government, and, as the figures show, spending is due to increase next financial year," an MoD spokesperson said. "Additionally, the budget increased defense spending by £2.9bln for next year, and we are committed to setting a path to 2.5% of GDP on defense in the spring."

The spokesperson added, "Our service personnel make extraordinary sacrifices to keep us all safe, and we are proud of their courage, dedication and professionalism. This is why we are renewing the nation's contract with those who serve – investing in our people, giving them the largest pay rise in decades, investing in military homes, and offering retention payments for key skills within the armed forces."

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The situation comes amid speculation that UK troops may be sent to Ukraine to train its armed forces. Last week, Defense Secretary John Healey described the moment as a "critical period" for Ukraine, adding that the UK is "stepping up" its assistance.