The vessel is currently docked in the French port of Marseilles until it receives permission from a country to continue its work under their flag. The Aquarius was stopped from flying the flag of Gibraltar last year but was renamed Aquarius II under the Panamanian flag. Now Panama says it will withdraw registration of the ship.

News of this impasse has led to growing calls for the government to allow the ship to re-register as a Swiss vessel. Four parliamentarians have submitted proposals for Aquarius to continue its work under a Swiss flag. On Monday, an open letter signed by several Swiss personalities and politicians was sent to the Federal Council.

On Tuesday, these calls were backed up with the petition signed by 27,000 members of the Swiss public handed in to the Federal Chancellery in Bern. But the decision could also have political consequences as Europe tries to stem the flow of African migrants to Europe. Italy has closed its ports to such vessels, forcing all but Aquarius to leave the area.

Chartered by Doctors Without Bordersexternal link (MSF) and SOS Méditerranéeexternal link, the Aquarius has rescued some 30,000 migrants in distress over two years. This year, more than 1,700 have died attempting to cross the Mediterranean.