Immigration, Asylum and Nationality Bill

I understand the reasons that my hon. Friend the Minister has given for allowing detainees to undertake paid work, and that requests have been made to that effect. However, detention centres are often run by private contractors who have not always earned the most sparkling reports from the prisons inspectorate. I am worried that detainees will end up being used as cheap labour. Will my hon. Friend say how that will be prevented?