UK-France small boats agreement demonstrated operational viability but lacked clear measures of success, ICIBI inspection finds

The Independent Chief Inspector of Borders and Immigration (ICIBI) on Tuesday published an inspection report of the 'one in, one out' small boats pilot scheme allowing the return of asylum seekers to France.

You can download the 40-page report here.

Known within the Home Office as Operation Hillmore, the agreement aimed at preventing dangerous Channel crossings. It was originally due to end on 11 June 2026 but was extended until 1 October. By mid-June, more than 1,000 people had been returned to France, while a similar number had been granted clearance to enter the UK.

The ICIBI report finds that that the agreement demonstrated that a jointly operated returns and admissions system could be established using existing, legally robust procedures, but clear measures of success had not been established when the pilot began.

The inspection attributed the programme's operational progress to strong leadership, central coordination and the high priority given to it within the Home Office, which enabled staff and financial resources to be directed towards the scheme.

Its broader objectives included deterring people from attempting Channel crossings, but inspectors said it was difficult to determine how much the agreement had contributed to any reduction in small boat arrivals, given the influence of other factors.

According to the report, there was ambiguity as to whether the Home Office considered 'success' of the pilot to mean delivering deterrence or establishing a workable operating model. 

The report states: "Although oversight, delivery planning, and evaluation arrangements were in place, including a delivery plan against which operational progress could be tracked, the pilot lacked sufficiently clear criteria for assessing its overall success. Monitoring focused on a range of operational metrics, but these measures were not tied to a coherent definition of success, limiting the ability to assess the pilot’s impact or demonstrate whether its overall aim had been achieved."

The report also raised concerns about the absence of a full value-for-money assessment and the impact of the scheme on other immigration enforcement activities, particularly the availability of detention spaces. 

It noted that France had rejected some referrals under the returns arrangement, with refusal rates reaching 50% in some cohorts. Inspectors said limited information about the reasons for refusals made it harder for UK officials to improve the process.

The ICIBI found that welfare and safeguarding considerations remained evident throughout the pilot, despite operational pressures. Inspectors said staff made efforts to treat individuals with dignity and respect, providing practical welfare support, improved reception arrangements and faster access to legal advice for those in detention. However, visits to Paris highlighted the vulnerability of people arriving in France after detention in the UK. 

As the inspection report notes, NGOs raised concerns over people being removed to France with minimal access to legal advice, giving insufficient opportunities for migrants to disclose potential trafficking or torture claims before or during detention. 

The Home Office had a dedicated legal team handling challenges to the scheme, and inspectors reported that, by 8 May 2026, around 100 judicial reviews had been successfully contested.

The report makes three recommendations to the Home Office: conduct a comprehensive lessons-learned exercise before key staff are redeployed; establish clear objectives and measurable success criteria for future pilots; and assess whether alternative approaches could deliver similar results more quickly and cost-effectively.

In its response to the report (available here), the welcomed the ICIBI report and the "significant strengths" identified by inspectors, and it accepted all three recommendations.