Italian Interior Minister Matteo Salvini said on Tuesday he was working to prevent two rescue ships operated by French and Spanish charities from bringing more than 500 migrants to Italy in the latest Mediterranean stand-off.

The Ocean Viking, which is run by French non-governmental groups (NGOs) Doctors Without Borders and SOS Mediterranee, has picked up some 356 migrants off the coast of Libya since Friday, while Spanish boat Open Arms has saved some 160 people.

Both vessels are in the central Mediterranean, within easy sailing distance of the Italian island of Lampedusa and are seeking a safe port to disembark the mainly African migrants.

But Salvini, the leader of the far-right League who has seen his popularity in Italy soar since he took office last year and launched a fierce anti-immigration crackdown, said on Tuesday the boats were not Rome’s problem.

“I am at work in the ministry this morning to prevent more than 500 migrants from disembarking from two NGO boats, one French and one Spanish,” Salvini wrote on Facebook.

“I will let you know how this ends. I will not give up.” Earlier this month, Salvini introduced a new law hiking fines for ships that enter Italian waters without authorisation to up to 1 million euros ($1.12 million).

It also provides for the arrest of captains who ignore orders to stay away and calls on naval authorities to seize their boats automatically.

Buoyed by his success in the polls, Salvini is looking to trigger an early election in the autumn by bringing down the Italian government, confident he would emerge as prime minister from any new vote. As such, a high-profile clash with foreign charities will bolster his anti-migrant credentials.

Salvini said Libya had offered to take back the migrants aboard the Ocean Viking and said Open Arms should go to Spain.

Doctors Without Borders has ruled out taking migrants to violence-plagued Libya, saying migrants are routinely tortured and abused there.

Open Arms has called for the European Union (EU) to coordinate the re-distribution of the migrants around the bloc.

The United Nations’ refugee agency called on European governments to intervene, warning that storms were approaching.

“To leave people who have fled war and violence in Libya on the high seas in this weather would be to inflict suffering upon suffering,” said Vincent Cochetel, UNHCR Special Envoy for the Central Mediterranean.

Cochetel said that “this is a race against time.” “They must be immediately allowed to dock, and allowed to receive much-needed humanitarian aid.” The official called on European governments to urgently allow in the rescued, but who remain stranded at sea as countries bicker over who should take them.

The UNHCR says nearly 600 people have died or gone missing in waters between Libya and Italy this year.

The European Commission says it’s urging member countries to take action and is offering support, but has no power to intervene.

A spokeswoman says “there’s nothing more we can do.” The MSF said late Monday in a tweet that it had completed “a critical rescue” of another 105 people onto the Ocean Viking, raising the total number of migrants on board ship to 356.

The captain of the Open Arms, Marc Reig, sent a letter on Monday to Spain’s embassy in Malta asking that Madrid grant asylum to the minors, saying they all “fulfil the conditions for recognition as refugees.” Spain said Italy should deal with the immediate care.

Asked if Madrid would agree to Reig’s request, Public Works Minister Jose Luis Abalos told private television Telecinco the Open Arms captain did not have the “legal competence or authority” to demand asylum for the minors.

“International law states that a rescue takes place in the closest safe port. Without doubt, right now that means Italy. If it was us, we would do it,” Abalos said.However, he also said Europe needed to forge a “wider” policy to handle migrant arrivals from Africa.

Abalos defended Spain’s record in rescuing migrants at sea, saying the coast guard had saved 50,000 migrants last year, echoing recent comments made by other Spanish ministers.

“It is not fair to question the government of Spain, or the reputation of the government of Spain, when it comes to the issue of rescues,” he added.

Agencies