Reform UK has proposed "Operation Fortress", a plan to deploy the Royal Navy, Royal Marines, RAF and British Army in the Channel to intercept migrant boats and return them to France or Belgium, which the party describes as the largest such military operation since the Second World War. Labour has dismissed the announcement as "reheated" rhetoric that offers "easy answers" rather than a genuine solution, while legal experts question whether the plan could actually be implemented within the bounds of domestic and international law. The proposal has reignited debate over how far military force can legally go in tackling small boat crossings.

While using the navy for logistics, surveillance and intelligence gathering (as happened between 2019 and 2023) would be lawful, directly intercepting, towing or pushing back boats raises serious legal problems. These include the risk of a common law offence if anyone is injured or killed, the universal right to claim asylum, obligations under maritime conventions such as the 1974 Safety of Life at Sea Convention and the 1982 UN Convention on the Law of the Sea to rescue those in danger, and the risk of violating French sovereignty, which could trigger diplomatic or trade tensions. Home Office figures cited in the article show 11,884 migrants arrived by small boat in the first six months of 2026.