Police in the French port of Calais arrested more than 40 migrants on Sunday after an attempt to board a cross-Channel ferry bound for Dover.
French police sprung into action after the migrants scrambled aboard a ferry docked at the port overnight. Twelve people are due to appear in court; the others were released with a warning.
The migrants broke into a highly protected area and used ladders to climb onto the ship. Cross-Channel traffic was delayed as police launched a 12-hour search for migrants hiding aboard.
Euronews reports that the migrants are trying to get to the UK before March 29, when Britain is set to leave the European Union.