Search and rescue ships operating in the Mediterranean face fines of up to €1 million (Dh4.1m) under a new law passed in a confidence vote by the Italian parliament.
The bill, first introduced in a decree issued in June by Italy’s hardline interior minister Matteo Salvini, will punish rescue boat captains with arrest if they dock with migrants and refugees without permission from the authorities.
Increased fines of between €150,000 and €1m, and the threat their ships could be confiscated are the latest obstacle to search and rescue operations in the region.
Previous legislation had imposed maximum fines of €50,000 for the unauthorised delivery of rescued migrants.
The government of the League and the anti-establishment 5-Star Movement has been riven by internal strife in recent weeks but won the vote by 160 to 57.
Other aspects of the new law target demonstrations, increasing the punishments for threatening or insulting public officials and throwing objects like flares.
Confidence votes are often used by Italian governments as a way of speeding legislation through parliament, truncating debate and sweeping away opposition amendments.
The result is seen as a victory for the interior minister’s far-right League party.
Mr Salvini has repeatedly clashed with NGOs conducting rescues off the coast of Libya with the aim of delivering them to Italy.
More than 121 rescued migrants are still on board the Spanish rescue ship Open Arms, which was denied entry to the port of Lampedusa last week.
In an interview with Spanish radio station Onda Cero, mission leader of NGO Proactive Open Arms Anabel Montes said they were "holding on," but cautioned that the longer it took for a solution to be found, the harder it would be.
Mr Salvini took to Twitter to remind the ship that Italian territorial waters are off limits and threatened that the authorities “are ready to seize the ship.”
In June, the German-flagged vessel Sea-Watch, captained by Carola Rackete, was seized when it entered the port of Lampedusa without permission.
Ms Rackete was later freed from house arrest, prompting Mr Salvini to denounce the judge who issued the ruling.
In July, the Italian government eventually reached a deal with five other European countries to house migrants who had been rescued by the Italian coastguard ship Gregoretti after a days-long ordeal for those prevented from disembarking.
Less than 24 hours later, another standoff began with the migrant rescue ship Alan Kurdi, which was blocked from entering Italian waters.
Mr Salvini's popularity has soared on the back of his uncompromising, anti-migrant position.
A poll by the Winpoll agency last week in Italy's business daily Il Sole 24 ore put support for the League at 39 per cent, making it easily the country's most popular party with more than double its share of vote at last year's parliamentary election.