Donald Trump said on Friday that farmers may be able to keep employing undocumented migrant workers without fearing enforcement raids under a system in which they would take “responsibility” for them.

Undocumented immigrants make up 4.6% of the U.S. workforce— more than 7 million people. Many of them work in agriculture, hospitality and construction, The Guardian reports.

Shay Myers, who runs Parma, one of the country’s largest onion farms, warned that “we will not feed our people without these workers,” considering that the Department of Agriculture estimates that over 40% of industry workers are undocumented.