<sod >The Government held an emergency Cobra meeting as the Calais ferry strike entered its fourth day, putting a labour dispute by French workers on a par with terrorist attacks and foot-and-mouth disease as threats to the nation.< eod>< sod > Calais had been closed to most ferry traffic for four days because of a strike by French ferry workers â a situation that prompted the Government to hold an emergency Cobra meeting, putting a labour dispute on a par with terrorist attacks and foot-and-mouth disease as threats to the nation.< eod>