LONDON — Europe’s unofficial “Let Them Drown” immigration policy came into force on Saturday with new naval patrols in the Mediterranean under orders to act as border guards rather than search and rescue teams. This, even when rickety boats carrying refugees from Syria and elsewhere in the Middle East and Africa are struggling to make it safely ashore.

Britain’s Conservative-led government said there should be no program to rescue drowning immigrants, arguing that the existence of a safety net had encouraged thousands more desperate people to attempt the dangerous maritime crossing than would have come otherwise.

That claim was hard to stand up. A U.K. Home Office official was unable to provide evidence to The Daily Beast or cite any studies that demonstrated a causal link between the increasing number of refugees and the existence of rescue boats. Political opponents of the government in London described the British government policy as a “barbarous abandonment of British values.”

Still, officials insisted that the rescue operations of Italy’s Mare Nostrum project had created an unintended “pull factor” for refugees attempting to flee violence and instability at home. The British government claimed that 3,000 migrants drowning at sea this year had proved that the rescue operation was counter-productive.

A senior Labour Party MP scoffed at what he suggested was faulty logic. “The increase in the number of deaths is not because they have put in place a more expansive search and rescue operation, that is just ludicrous,” said Barry Gardiner, who pointed to the changing circumstances overseas.

In recent months record numbers of refugees from Syria have spilled into North Africa, swelling the ranks of displaced people who are willing to risk a perilous journey on overcrowded boats. The push factor of a Syrian civil war that has killed more than 200,000 people is a more probable cause of people setting to sea than the attraction of a voyage into the arms of a European navy.

In response to a deadly shipwreck that killed more than 400 migrants off the coast of Italy’s Lampedusa island last year, the Italian Navy’s Mare Nostrum operation has been scanning the seas looking for listing vessels. They have rescued more than 150,000 people so far from unsafe fishing boats that left the coasts of Tunisia and particularly Libya, where the ports are now virtually lawless.

Unlike economic migrants that used to make the crossing to find work in Europe, more than three-quarters of the migrants who have come over in the last 12 months are seeking political asylum, according to the Italian Foreign Ministry. Of those rescued, almost half are women and children.

The European Union’s operation Triton, which came into force on Saturday, is supposed to replace Mare Nostrum. But it will not attempt to replicate its search-and-rescue mission. It has a third of the budget and a fraction of the maritime vessels. Ships and aerial surveillance craft from Frontex, Europe’s border agency, will simply report any problems to the Italian coastguard.

Without a dedicated and proactive rescue force, campaigners fear, the death toll in the Mediterranean will skyrocket.

Britain and some of its allies in Northern Europe apparently believe that removing these protections will in fact help to stem the flow of migrants.

James Brokenshire, Britain’s Immigration Minister, said those wanting to reach European soil were using Mare Nostrum as a kind of naval taxi service.

“Traffickers have taken advantage of the situation by placing more vulnerable people in unseaworthy boats on the basis that they will be rescued and taken to Italy,” he told the House of Commons. “But many are not rescued, which is why we believe that the operation is having the unintended consequence of placing more lives at risk.”

Britain’s claims have caused consternation among those dealing with the crisis. An Italian Interior Ministry official told The Daily Beast that issues in Africa offered a more accurate explanation. “The influx is due to a number of factors, starting with the lack of control in Libya,” he said. “Mare Nostrum has saved lives, and we have caught more than 60 human traffickers who are now facing judicial action who will not be able to continue their work.”

David Cameron, the British Prime Minister, is under intense pressure from within his own party to take a more aggressive position on immigration because of the increasing electoral support for UKIP, an upstart right-wing party that wants to close the borders.

“I would dearly love to believe that this has nothing to do with the tensions within the Conservative Party and the pull of its own right wing towards UKIP,” said Labour’s Gardiner. “I would like to believe that this is a decision—albeit a wrong-headed one—that is based on financial considerations and a bit of false logic.”

While Europe’s political leaders wrangled over maritime patrols and who would pay for them, the men and women on the front line of the immigration battle were continuing to do their job. For now, at least.

Captain Giuseppe Maggio described the nightmare situations the Mare Nostrum ships encounter. “We’ve seen things I cannot describe,” he told AFP in Palermo last week. “The hardest moment was one shipwreck when we managed to rescue 250 people, but with rough seas, at night, we weren’t able to save everyone.”

Even with Mare Nostrum, death at sea is unavoidable. More than 3,300 migrants are known to have been lost in the last 12 months according to the United Nations Refugee Agency. Many of their bodies get caught up in fishing nets or disappear forever. When the body counts are high, the Mare Nostrum sailors have to nail the coffin lids so they stack better or, in one case last summer they haul in the rickety boats with the corpses still in the hulls.

“Timing is everything. You need to keep your nerve and make sure they know everything’s going to be ok,” Maggio told AFP. “We’re dealing with people who often cannot swim, don’t speak our language and are exhausted from days in the sun. The key is to prevent panic.”

Even as Italy’s Interior Minister Angelino Alfano promises his constituents that the Mare Nostrum program, which costs the Italian government some €11 million a month, is about to end, the Italian Navy promises that it will continue the mission. Commander-in-Chief Adm. Filippo Maria Foffi told a conference in Brussels that the fleet has no plans to cease the searching and rescuing. “At the moment, no one has told us to stop the mission,” he said. The Italian Navy confirmed to The Daily Beast on Friday that it will continue its missions “for the foreseeable future.”

Triton will begin patrolling the seas with six ships based in Lampedusa and Porto Empedocle in Sicily on November 1. Ten days later, it will start air missions using two airplanes and one helicopter. Because it is not authorized to rescue migrants, it will still have to call Italian officials to conduct rescues when it sees ships in trouble.

Amnesty International said that Italy “must continue the Mare Nostrum search and rescue operation until there is a better-equipped alternative supported by other European nations.” In a statement, John Dalhuisen, Amnesty’s Europe and Central Asia director said, “Frontex’s Triton operation does not begin to meet the needs of thousands of migrants and refugees, including those forced to flee war and persecution in the Middle East and Africa. The suggestion that it could replace Mare Nostrum could have catastrophic and deadly consequences in the Mediterranean.”