Key Takeaways
- France and the United Kingdom have renewed the Sandhurst Treaty for three more years, extending the 2018 agreement aimed at curbing illegal Channel crossings.
- The UK will contribute up to €766 million over the period, with a guaranteed €580 million and a conditional “flexible” tranche of €186 million tied to measured effectiveness.
- Police presence on the French side of the Channel will be doubled to nearly 1,400 officers by 2029, backed by a French Republican Security Corps (CRS) unit equipped with drones, helicopters and electronic surveillance.
- A new administrative detention centre in Loon‑Plage (near Dunkirk) will hold foreign nationals subject to an obligation to leave French territory (OQTF) pending deportation.
- UK officials report 41,500 small‑boat arrivals in 2025—the second‑highest yearly total since 2018—while French authorities claim arrivals have halved compared with the same period in 2025.
- Prime Minister Keir Starmer praised the deal as a “landmark” that strengthens intelligence, surveillance and ground presence, asserting it has already prevented tens of thousands of crossings.
- An additional “one‑in‑one‑out” arrangement (Operation Hillmore) lets the UK return an equivalent number of small‑boat arrivals to France in exchange for admitting migrants from France who have not attempted the crossing.
Renewal of the Sandhurst Treaty
After several months of negotiations, France and the United Kingdom have formally agreed to renew the Sandhurst Treaty for the next three years. Originally signed in 2018, the treaty was designed to curb the surge of irregular migrants attempting to cross the English Channel in small boats. Its first extension occurred in 2023, and the current renewal pushes the agreement’s expiry date to 2026. The refreshed pact reaffirms both nations’ commitment to joint operational measures, intelligence sharing, and resource allocation aimed at reducing unsafe Channel crossings and enhancing border security on both sides of the waterway.
Financial Commitments and Conditional Funding
Under the renewed arrangement, British authorities will be able to provide funding of up to €766 million over the three‑year span. This total comprises a guaranteed baseline contribution of €580 million—an increase from the previous €540 million pledge—plus a so‑called “flexible part” valued at €186 million. The flexible tranche is conditional upon the demonstrated effectiveness of the measures implemented under the treaty; if agreed‑upon benchmarks are met, the UK will release the additional funds, otherwise the amount may be adjusted downward. This structure is intended to incentivise tangible results while giving London flexibility to respond to evolving circumstances on the ground.
Expansion of Police Presence and Surveillance Assets
A central component of the renewed treaty is the significant increase in law‑enforcement resources dedicated to monitoring the Channel. The number of French police officers assigned to patrol the maritime border will be doubled, rising to almost 1,400 by 2029. To bolster these ground forces, a dedicated Republican Security Corps (CRS) unit—financed by France—will be deployed to the area. The CRS will be equipped with modern assets, including drones, helicopters, and various electronic surveillance systems, enabling real‑time tracking of vessels and rapid response to suspected smuggling or migrant‑crossing attempts. The combined increase in personnel and technology aims to create a denser, more responsive security net along the French coastline.
Operational Details of the New Detention Facility
On Thursday, French Interior Minister Laurent Nuñez and his UK counterpart Shabana Mahmood are scheduled to visit the construction site of an administrative detention centre in Loon‑Plage, situated near the northwestern city of Dunkirk. Once operational, the facility will hold foreign nationals who are subject to an obligation to leave French territory (OQTF) pending their scheduled deportations. By centralising the detention of individuals awaiting removal, the centre seeks to streamline the removal process, reduce the likelihood of absconding, and improve coordination between French immigration authorities and UK enforcement partners. The visit underscores the practical implementation of the treaty’s broader strategy, which couples deterrence at sea with efficient on‑shore processing of those who do manage to reach French soil.
Channel Crossing Statistics and Differing Narratives
UK officials report that an estimated 41,500 people crossed the Channel to reach the United Kingdom in 2025 aboard small boats, commonly referred to as dinghies. This figure marks the second‑highest annual total since such crossings began being recorded in 2018, highlighting the persistent pressure on both nations’ border regimes. In contrast, French authorities claim that, since the beginning of the year, arrivals in the UK have halved compared with the same period in 2025. The discrepancy reflects differing metrics and timeframes: the UK cites cumulative yearly arrivals, while France points to a recent decline observed in early‑year data. Both sides acknowledge that fluctuations are influenced by weather, smuggling network adaptations, and the effectiveness of joint patrols, underscoring the need for continued vigilance and adaptive tactics.
Political Endorsement and Claims of Impact
Prime Minister Keir Starmer welcomed the renewed agreement as a “landmark” development, asserting that it “takes things further by strengthening intelligence, surveillance and presence on the ground to protect the UK’s borders.” He emphasized that the Anglo‑French collaboration has “already prevented tens of thousands of crossings,” suggesting that the measures instituted under the original Sandhurst Treaty and its first extension have yielded measurable deterrence. Starmer’s remarks aim to reinforce domestic confidence in the government’s immigration policy while highlighting the tangible benefits of sustained bilateral cooperation. The endorsement also serves to signal to both publics and stakeholders that the partnership remains a cornerstone of the UK’s broader border security strategy.
Supplementary “One‑in‑One‑Out” Arrangement (Operation Hillmore)
In the summer of 2025, alongside the treaty renewal, the two governments signed an additional agreement colloquially known as the “one‑in‑one‑out” or Operation Hillmore. This arrangement permits the United Kingdom to return a number of small‑boat arrivals to France, provided that an equivalent number of migrants from France who have not attempted to cross into the UK are admitted to British territory. The mechanism is designed to balance humanitarian obligations with deterrence goals: it allows the UK to enforce return policies while offering a legal pathway for certain migrants, thereby reducing the incentive for dangerous crossings. Operation Hillmore represents a pragmatic effort to manage flow dynamics, alleviate pressure on reception facilities, and maintain cooperative spirit even as enforcement measures tighten.
Overall Implications for Franco‑British Border Cooperation
The renewal of the Sandhurst Treaty, accompanied by increased financial commitments, expanded police and surveillance capabilities, the establishment of a dedicated detention centre, and the supplemental one‑in‑one‑out deal, reflects a comprehensive approach to managing Channel migration. By combining deterrence at sea with efficient on‑shore processing and reciprocal return mechanisms, France and the UK aim to curb irregular crossings while upholding international obligations. The ongoing dialogue, highlighted by joint ministerial visits and public statements from leaders such as Prime Minister Starmer, suggests that both capitals view the partnership as essential to regional security and are willing to adapt the framework as circumstances evolve. Continued monitoring of outcomes—particularly the effectiveness‑linked flexible funding and the statistical trends in crossings—will be critical in assessing whether the renewed treaty meets its stated objectives over the next three years.