The ship, the only charity-operated rescue boat working in the central Mediterranean, has been repeatedly turned away by Italy and been forced to stop in Malta and Spain after missions in recent months.
On Monday SOS Mediterranee, the charity which runs it, said its “only option” after picking up 58 migrants in its latest rescue was to head to the
southern French port of Marseille where the NGO is headquartered.
“We alerted other countries but we find it hard to imagine that France would refuse, given the humanitarian situation,” said Francis Vallat, the head
of SOS Mediterranee's French operations.
But the French government appeared reluctant to welcome the boat — which has become a bitter symbol of European divisions over migration — to dock.
France wants the ship to disembark its latest passengers at “the nearest safe port” under “a European solution”, the prime minister's office told AFP.
On Tuesday France's economy minister said Paris has turned down the boat's request to dock in Marseille.
“There are European rules. A boat with migrants on board must head to the closest European coastline. And the port of Marseille is not the closest. For the moment France has said 'no', because if we need to have a coherent policy on migration then we need to respect European rules.”
The Aquarius is currently near the Libyan coast, about four days from Marseille, according to Vallat.
The charity's director Frederic Penard told reporters that 58 migrants were onboard, including 17 women and 18 children.
Additional rescue operations might be carried out on the ship's voyage toward France, he added.
Flag at risk
The charity has refused calls by Italy and others to return the rescued migrants to Libya, saying the country — riven by conflict between rival armed groups — is not safe for refugees.
French President Emmanuel Macron has previously accused Italy of breaching international maritime law by turning away the Aquarius because the country is the closest to areas where the boat operates.
He was criticised at home for not offering safe haven to the Aquarius after it first became stranded in June, although France eventually offered asylum to about 80 rescued migrants.
His centrist government passed a controversial immigration law in August which it insists strikes a balance between granting faster asylum while allowing faster deportation of those rejected as “economic” migrants.
Italy's far-right Interior Minister Matteo Salvini accuses the Aquarius of offering a “taxi service” to Europe for migrants in Libya and has said it is permanently barred from Italian ports.
SOS Mediterranee and fellow charity Doctors without Borders (MSF), which operate the boat jointly, suffered a major setback Saturday when Panama said it would stop allowing the Aquarius to fly its flag at sea.
The decision came after Gibraltar withdrew authorisation for the Aquarius to use its flag in August, potentially leaving the boat stuck in legal limbo.
“We risk losing our Panama flag as soon as we reach land,” Penard said.