the transport workers ' union 's national secretary of the transport workers ' union , tony sheldon , accused aldi of trying to reintroduce serfdom .
` major retailers like aldi are trying to turn the clocks back on our modern society to reintroduce serfdom .
aldi 's last attempt to increase workers hours in 2012 failed despite the supermarket chain arguing that their employees ` overwhelmingly supported ' and ` preferred ' the proposals .