Five aid groups that operate migrant rescue ships in the Mediterranean have refused to sign up to the Italian government’s code of conduct, the Interior Ministry said, but three others backed the new rules.

Charity boats have become increasingly important in rescue operations, picking up more than a third of all migrants brought ashore so far this year against less than one percent in 2014, according to the Italian coastguard.

Italy, fearing that the groups were facilitating people smuggling from North Africa and encouraging migrants to make the perilous passage to Europe, proposed a code containing around a dozen points for the charities. Those who refused to sign the document had put themselves “outside the organised system of sea rescues, with all the concrete consequences that can have”, the ministry said.

Italy had previously threatened to shut its ports to NGOs that did not sign up, but an source within the Interior Ministry said that in reality those groups would face more checks from Italian authorities.

Doctors Without Borders (MSF), which has taken part in many of the rescues of the 95,000 migrants brought to Italy this year, attended a meeting at the Interior Ministry but refused to sign the code. MSF objected most strongly to a requirement that aid boats must take migrants to a safe port themselves, rather than transferring people to other vessels, which allows smaller boats to stay in the area for further rescues.

“Our vessels are often overwhelmed by the high number of [migrant] boats … and life and death at sea is a question of minutes,” MSF Italy’s director, Gabriele Eminente, wrote in a letter to the interior minister, Marco Minniti. “The code of conduct puts at risk this fragile equation of collaboration between different boats,” he continued, adding that MSF still wanted to work with the ministry to improve sea rescues.

But Save the Children backed the measures, saying it already complied with most of the rules and would monitor constantly to be sure that applying them did not obstruct their work. “We would not have signed if even one single point would have compromised our effectiveness. This is not the case – not one single point of the code will hinder our activities,” said Valerio Neri, director of Save the Children Italy, after the meeting.

The Malta-based Migrant Offshore Aid Station (MOAS) and Spanish group Proactiva Open Arms agreed to the conditions, but Germany’s Sea-Watch, Sea-Eye and Jugend Rettet, and France’s SOS Mediterranée abstained. MSF, SOS Mediterranée and Jugend Rettet also called for clarification of the rules and took issue with a clause in the code that would oblige groups to allow police officers on board.

“For us, the most controversial point … was the commitment to help the Italian police with their investigations and possibly take armed police officers on board,” Jugend Rettet coordinator Titus Molkenbur said. “That is antithetical to the humanitarian principles of neutrality that we adhere to, and we cannot be seen as being part of the conflict.”

