The supposed “turn-around” policy for migrant boats is similar to previous reports of wave machines or floating fences. It sounds tough but will never be implemented.

Policies aimed at the interception or interdiction of asylum seekers at sea are fairly common. Australia, the United States, Italy, Greece and Spain have all done it. It can be done consistently with international refugee law: intercepting refugees at sea and transporting them to a genuinely safe third country does not breach the non-refoulement obligation imposed by Article 33 of the Refugee Convention because it does not force the refugees back into the arms of their persecutors.

But in those examples, the asylum seekers concerned are placed into the arms of someone else. By contrast, the French are not cooperating with Priti Patel’s supposed plan. A letter to that effect from her counterpart, Ministre de l’Intérieur Gérald Darmanin, has mysteriously found its way to British journalists:

… the French position on intervention at sea remains unchanged. Safeguarding human lives at sea takes priority over considerations of nationality, status and migratory policy, out of strict respect for the international maritime law governing search and rescue at sea… The use of maritime refoulments to French territorial waters would risk having a negative impact on our cooperation.

I am not an expert on international maritime law, but as Professor Erik Røsæg summarises the position: “there is a duty and a right to render assistance to persons in danger at sea. This duty applies regardless of whether the rescue operations are believed to have an undesired pull effect, motivating refugees and migrants to travel”. The French position is therefore understandable.

Without French cooperation, what does “turnaround” mean? Towing a small boat back out to sea with insufficient fuel to resume its journey to the UK? It is obvious how dangerous that is for the passengers. They may well die. Exactly that occurred in the Mediterranean in 2011, when a boat from Libya carrying 72 passengers was left adrift for two weeks. Only nine people survived.

Or will Border Force officials try and judge to leave the small boat passengers with enough fuel to get to France but not the UK? What immigration official would actually, in real life, be willing to do that? Morality aside, it might raise manslaughter liability and would surely raise civil liability under the right to life in Article 2 of the European Convention on Human Rights. The immigration officer trade union is understandably hostile and has already declared the idea “dead in the water” (dark pun possibly intended).

No sensible person is actively in favour of Channel boat crossings. They are very dangerous; it is only a month since someone last drowned. The available policy and legal options available to the government are very limited. It is hard to imagine that even more security would help the situation.

Deterrent policies — by which I mean treating people really badly when they get here in order to send a message to others and deter them from coming — simply do not work. The Borders and Nationality Bill currently before Parliament fits into this mould. Safe and legal routes to claim asylum are important and should be expanded but it may be unrealistic to imagine they would significantly reduce demand to reach the UK by other means.

It has long been obvious that if the government were actually serious about stopping the boats, it would need to negotiate with the French and/or EU and reach an agreement. The “turn-around” controversy only reinforces this point.

All this hostile posturing makes a deal with France less, not more, likely.