Quick schoolboy French guess: "laisser nous travail" sounds like "let us work" and "mobiliser vs urgent" sounds like "get us moving asap".
SeaFrance Nord Pas de Calais should be leaving Dover today as she is on the Dunkerque port website as arriving at 1430.
http://www.dunkerque-port.fr/en/commercial-activities/ships-entry-transit.htm
Incidentally, Arno's, the ship repair yard in Dunkerque, is also in financial trouble. Partly because they are still owed 3m Euros by Sea France for the conversion of the Moliere some years ago. The other French ship repair yard, Sobrena at Brest, is also in trouble although nothing to do with Sea France.