Speaking to the BBC from Singapore, Hammond said: "So long as there are large numbers of pretty desperate migrants marauding around the area, there always will be a threat to the tunnel security.
"We’ve got to resolve this problem ultimately by being able to return those who are not entitled to claim asylum back to their countries of origin."
He went on to claim that "Europe can’t protect itself, preserve its standard of living and social infrastructure if it has to absorb millions of migrants from Africa".
Hammond's use of the term ‘marauding’ has drawn widespread criticism. Politicians, PR professionals, journalists and the general public have pointed out that not all migrants should be portrayed as criminals – with many attempting to escape war and persecution.
Last month, Prime Minister David Cameron was branded 'disgraceful' and accused of 'dehumanising' migrants when he described them as a "swarm".
Philip Hammond: "Marauding migrants threaten our standard of living" No. Generations of immigrants helped build up UK http://t.co/Q6vdKGDanw— Diane Abbott (@HackneyAbbott) August 9, 2015
Philip Hammond claims "marauding migrants threaten our standard of living". Xenophobic "them & us" personified. pic.twitter.com/Ii2mYed2Ky— James Melville (@JamesMelville) August 10, 2015
Welcome back Enoch Powell! 'Marauding' migrants threaten our standard of living, says Philip Hammond http://t.co/R7uADvLoBt— Mariella Frostrup (@mariellaf1) August 10, 2015
Compare and contrast frightened ninny Phillip Hammond on migrants and Barack Obama's optimism on #Africarising— Paul Nettleton (@PaulANettleton) August 10, 2015
Marauding migrants threaten a continent's standard of living, says Philip Hammond. Pretty good description of the British Empire— Musa Okwonga (@Okwonga) August 9, 2015
Google define : marauding adjective going about in search of things to steal or people to attack. "marauding gangs of youths"— Krishnan Guru-Murthy (@krishgm) August 9, 2015