London (AFP) - London and Paris were working Thursday to thrash out a deal on undocumented migrants crossing the English Channel in small boats on the last day of the French president’s state visit to Britain.

UK Prime Minister Keir Starmer and France’s Emmanuel Macron posed for the cameras outside Downing Street, as they headed inside for a summit with senior ministers focused on that issue and other shared concerns.

They include the volatile situation in the Middle East, continued support for Ukraine and a “reboot” of defence ties including joint missile development and nuclear co-operation.

The two leaders agreed Wednesday that there was a need for a “new deterrent” to curb the small boat crossings.

The issue has become a major headache for Starmer’s year-old Labour government as support for the upstart anti-immigrant Reform UK party soars.

The UK would tackle undocumented migration with “new tactics” and a “new level of intent”, Starmer said in summit opening remarks, adding: “We will agree the situation in the Channel cannot go on as it is.”

A so-called “one in, one out” migrant deal, details of which were reportedly still being discussed, would see migrants sent back to France in return for the UK accepting a similar number of migrants with strong asylum cases.

As the leaders met, the UK Coastguard said a number of the small boats headed to southeast England had been sighted in the Channel.

Reform UK leader Nigel Farage meanwhile posted a video and photo on X from another boat showing the scene in the waterway between Britain and France – one of the world’s busiest shipping lanes.

Describing it as a “classic” scenario over the past five years when the sea was calm, he described seeing “about 70 people on board being escorted all the way over by the French Navy” with UK Border force “waiting for the handover”.

- Pomp and politics -

The mooted migrant-exchange scheme, which has sparked “serious concerns” among some other European nations, could initially involve around 50 people a week, French daily Le Monde reported.

More than 21,000 migrants have made the Channel crossing in rudimentary vessels this year alone.

During a meeting with Macron on Wednesday, Starmer outlined his government’s policies to tackle issues such as illegal working, a Downing Street spokesperson said.

Illegal employment opportunities are one of the “pull factors” France claims has made the UK particularly attractive to migrants.

Thursday’s summit follows two days of events spanning pomp and politics, trade and culture for Macron and his wife Brigitte.

The French first couple were welcomed on Tuesday by King Charles III and Queen Camilla with a horse-drawn carriage procession, a 41-gun salute and a banquet at Windsor Castle, west of London.

- Ukraine focus -

As part of a mooted defence agreement, the UK and France would order more Storm Shadow cruise missiles – long-range, air-launched weapons jointly developed by the allies – while stepping up work on a replacement system, the UK defence ministry said.

The missiles have been shipped to Ukraine in significant numbers to help Kyiv in its war with Russia following Moscow’s full-scale 2022 invasion.

Starmer and Macron will also on Thursday dial into a meeting of the so-called “coalition of the willing” on Ukraine.

Britain and France are spearheading talks among the 30-nation coalition on how to support a possible ceasefire in Ukraine, including potentially deploying peacekeeping forces.

Starmer’s office said this week that the call would “discuss stepping up support for Ukraine and further increasing pressure on Russia”.

They will speak with Ukrainian President Volodymyr Zelensky, German Chancellor Friedrich Merz and Italian Prime Minister Giorgia Meloni, according to the French presidency.

The state visit also saw Macron formally announce the loan of the famous Bayeux Tapestry, depicting the 1066 Norman conquest of England, to the British Museum for 10 months from September 2026 in return for a number of English treasures.