Ahead of the start of the party’s conference, Reform UK’s MPs have been repeating their claim that migrants who are intercepted while crossing the English Channel can just be taken back to France.

It’s part of the party’s four point plan to “stop the boats”.

Both the party’s leader Nigel Farage and deputy leader Richard Tice have claimed that the UK is legally entitled to do this.

But BBC Verify has found no evidence that this is the case.

Earlier this month, Richard Tice tweeted: “Starmer needs to explain why he does not have leadership & courage to use 1982 UN Convention of Law at Sea to pick up & take back”.

On 19 September, Nigel Farage told BBC Radio Kent that part of Reform’s plan for migrants crossing the Channel in small boats would be to “take them back to France”.

In June, he said on Question Time: “We’ll pick them up in the Channel and take them back” to France.

He said he would use the Royal Marines to do this, if necessary.

But it is not clear how Reform could do this without breaching international law.

According to the United Nations Convention on the Law of the Sea (UNCLOS) and the International Convention on Maritime Search and Rescue (SAR Convention), states are allowed to pick people up from boats if they are “found at sea in danger of being lost”.

But these laws do not allow them to be taken to another state without that country agreeing.

In fact, Article 19 of UNCLOS says that if a “foreign ship” enters another country’s territorial waters it will “be considered to be prejudicial to the peace” if “it engages in the loading or unloading of any… person contrary to the immigration laws” of that country.

BBC Verify spoke to two experts in maritime law.

James M. Turner KC, a shipping lawyer at Quadrant Chambers, told us: “The French would have to grant express permission for UK vessels to carry rescued people through their territorial waters and to leave them ashore in France”.

Ainhoa Campàs Velasco, a maritime law expert from the University of Southampton, said migrants could not be returned to French shores, “unilaterally, and without prior agreement with France”.

There is no such agreement between the UK and France.

The two countries agreed a joint action plan in 2019, which does provide for cooperation, but it does not allow one country to bring people rescued in the English Channel to the other country’s ports.

Richard Tice has repeatedly claimed that he had been advised it would be legal, but we have had no response to requests to see that advice.

We asked both the Home Office and the French authorities whether the UK would be legally entitled to pick people up and return them to France, but they would not comment.

There was one occasion in July when a British Border Force vessel was called to assist a French search and rescue operation off the coast of Gravelines in northern France.

The British vessel, together with the French ship involved, both took the people they had rescued to Calais.

Mr Turner explained that could happen because British vessels were assisting a French rescue operation, and were in French waters with French permission.

Prime Minister Keir Starmer stressed it had been an operational decision taken at the time and was not a change of policy.

In 2021, the UK government considered turning back small boats intercepted in the English Channel but the plan never went ahead.

On 3 September, Richard Tice said about his policy of taking people intercepted in small boats straight back to France: “We know it’s legal because the Belgian authorities have done it.”

BBC Verify spoke to the Belgian police when the claim was first made in May, and they confirmed that they have intercepted small boats, treating them “as a rescue operation”.

But they said these boats very rarely cross to the UK from the Belgian coast because of the distance to the UK and strong currents which make the crossing very dangerous.

We put the claim that the Belgian authorities have taken migrants back to France to the Federal Police in Belgium and they told us “this is not correct”.