How UK-France ‘one in, one out’ migration deal will work – and what the challenges could be

After weeks of rising Channel crossing figures, the UK government has agreed on a long-awaited migration deal with France. Keir Starmer and Emmanuel Macron announced a “one in, one out” pilot – and the UK prime minister said the “groundbreaking” scheme could start returning migrants to France within weeks. The deal was announced alongside a separate agreement to coordinate the use of French and British nuclear weapons.

The migration agreement will allow the UK to return selected numbers of small boat arrivals to France. In exchange, the UK will admit an equal number of asylum seekers with legitimate ties to the UK (such as family), who have not previously attempted to enter the country illegally.

The plan will start as a pilot, with initial reports suggesting the UK could return up to 50 people per week (2,600 per year). That is roughly 6% of small boat arrivals in 2024. The remaining arrivals will continue to be processed under the UK’s existing system.

The “one in, one out” system appears similar to an agreement in 2016 between the EU and Turkey. Under that scheme, for every irregular migrant returned from the Greek islands to Turkey, one Syrian refugee who had stayed in Turkey could be legally resettled in the EU. Under the EU–Turkey deal, only 2,140 migrants were returned to Turkey by 2022, compared with over 32,000 who were resettled in the EU.

The British government’s hope is that this pilot will lay the groundwork for a broader EU-UK return framework that would allow it to return more people. Before Brexit, the UK was part of the EU’s asylum framework, the Dublin regulation. This allowed any EU country, including the UK, to return asylum seekers to the first EU country they entered or passed through.

From 2008 to 2016, the UK was a net sender of asylum seekers: it returned more people to EU states than it accepted, receiving fewer than 500 people annually. The trend reversed after 2016, with the UK accepting more migrants than it returned.

But southern EU countries could complicate any expansion or permanent implementation of the pilot. Italy, Spain, Greece, Malta and Cyprus have opposed a UK–France agreement, fearing it would lead to more people being sent back to them – southern European states are where migrants typically arrive in the EU first.

Challenges ahead

The deal is a significant step for a UK government that has struggled to control the narrative on migration. Losing ground to Reform, the government has recently proposed tightening legal immigration rules, including by making it harder and longer to acquire British citizenship, and by cutting legal migration routes.

It also marks a notable shift in the UK’s post-Brexit migration strategy. But questions remain about the details and implementation.

The French president hailed it as a “major deterrent” to Channel crossing, as migrants would not remain in the UK but be returned to France. Macron said that one-third of arrivals in France are heading towards the UK. So it follows that any deterrent from Channel crossings would also lead to a reduction in people coming to France.

Yet, as I have shown in my research, deterrence is rarely effective. This is because information about deterrence factors does not necessarily reach the asylum seekers or stop smugglers. It also does not address the underlying drivers of migration, such as poverty, conflict and corruption.

Moreover, returns are notoriously difficult to enforce. Many asylum seekers lack documentation, and complex legal processes raise administrative and financial costs.

Scalability also poses a challenge, given EU countries’ divided stances on an EU-wide deal.

It is, however, promising that the UN refugee agency has given the agreement its backing, stating: “If appropriately implemented, it could help achieve a more managed and shared approach, offering alternatives to dangerous journeys while upholding access to asylum.”

The last UK government’s attempts to deter Channel crossings, such as the Rwanda scheme, had led to the agency raising serious concerns.

How many asylum seekers does the UK take?

This deal comes amid an increase in asylum applications in the UK. Annual applications rose from 38,483 in 2018 to over 108,000 in 2024.

In just the first half of 2025, small boat arrivals increased 48% compared with the same period in 2024, exceeding 20,000. By contrast, irregular arrivals to the EU decreased by 20% in the first half of 2025, mainly driven by a drop in arrivals to Greece and to Spain’s Canary Islands.

When accounting for population, the UK receives fewer asylum applications – 16 for every 10,000 people living in the UK – than the EU average (22 per 10,000).

Data shows that between 2018 and 2024, 68% of small boat asylum applications processed in the UK were approved, indicating that most were made by people in genuine need.

UK–France migration cooperation dates back to the 1990s, but since 2019, the focus has been on addressing the rise in Channel crossings.

A significant step was the UK-France joint declaration of March 2023, under which the UK committed €541 million (approximately £476 million) between 2023 and 2026. Funds were allocated for assets including drones, helicopters and aircraft, and for the creation of a migration centre in France. Importantly, the agreement sought to increase surveillance along the French border, rather than return migrants.

This cooperation deepened in February 2025, when both countries agreed to extend their partnership to 2027 and reallocate €8 million for new enforcement measures.

Joint maritime activities have played a role too: since October 2024, UK Border Force vessels have entered French waters on three occasions to assist boats in distress and return people to the French coast.

Overall, this new agreement represents a milestone in UK–France migration cooperation, and the UK’s first significant post-Brexit returns scheme with an EU country. While questions remain over its scalability – given the modest return numbers, legal and logistical hurdles, and European political divides – it is a crucial step in cross-Channel cooperation on migration and asylum, making progress on what has been an intractable problem for UK governments.

Matilde Rosina does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.