The senior Tory politician was sharply criticized by Labour MPs for scaremongering, after he told the BBC that the solution to the Calais migrant crisis was to return hopeful economic migrants back to their country of origin.
READ MORE: UKIP MEP says he stopped 25 Calais migrants from entering Britain
Speaking during a visit to Singapore on Sunday, Hammond said Africans will always want to make their way to Europe.
“The gap in standards of living between Europe and Africa means there will always be millions of Africans with the economic motivation to try to get to Europe,” he 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.”
Hammond argued the current migration laws aren’t “sustainable” because potential immigrants are “confident” they wouldn’t be sent home.
“Now that is not a sustainable situation because Europe can’t protect itself, preserve its standard of living and social infrastructure if it has to absorb millions of migrants from Africa,” he said.
His comments were criticized by Labour leadership hopefuls Yvette Cooper, Liz Kendall and Jeremy Corbyn.
Shadow Home Secretary Cooper said his remarks were “alarmist and unhelpful,” adding that many of the migrants were fleeing conflict.
“As NGOs have pointed out, many of those crossing the Mediterranean are fleeing a terrible conflict and humanitarian crisis in Syria,” she said.
“Yet Britain is doing too little to help address the European refugee issue. We need practical responses to help refugees, stop people smuggling, and prevent illegal travelling – and European countries need to work together to implement them, not just resort to divisive statements instead.”
Hammond’s comments come just a week after Prime Minister David Cameron told ITV News that the migrants in Calais were part of a “swarm of people coming across the Mediterranean” to find economic prosperity in Britain.
Labour leadership candidate Andy Burnham tweeted in response to the comments: “Cameron calling Calais migrants a ‘swarm’ is nothing short of disgraceful. Confirms there’s no dog-whistle these Bullingdon Boys won’t blow.”
In order to tackle the problem, Britain will fund 1,000 guards on the French side of the Channel tunnel, it was announced last week.
The numbers of migrants in a Calais camp, known as The Jungle, have soared over the past few months from 1,000 in April to nearly 5,000 by August.
Many have attempted to reach Britain by boarding trains through the tunnel or on freight lorries bound for UK destinations.
At least nine people have died so far this year trying to enter the UK.