An inspection report on the UK-France Agreement on the Prevention of Dangerous Journeys, known as Operation Hillmore, was published on 10 November 2026 by the Independent Chief Inspector of Borders and Immigration. Initially a ten-month pilot, Hillmore tested returning to France people who arrived in the UK illegally by small boats while providing a controlled legal route for eligible migrants in France to enter the UK. It was due to end on 11 June 2026 but was extended until 1 October 2026.

The inspection found the pilot showed a jointly linked IN and OUT agreement could be established and made to work using existing, legally robust practices. It credited the priority and resources given to Hillmore within the Home Office and strong leadership coordinating work across the migration and borders system. However, it found clear criteria for assessing overall success were not set at the outset, and the pilot's stated aims focused on high-level objectives such as deterrence, where multiple factors were in play, making its specific contribution to any reduction in small boat arrivals difficult to evaluate.

The report calls for an extensive lessons-learned exercise as soon as possible, before key staff are redeployed, and makes three recommendations on the design, delivery and evaluation of future Home Office pilots. The report was sent to the Home Secretary on 16 July 2026, and the Home Office has fully accepted all three recommendations, the inspector said.