Apprenticeships, Skills, Children and Learning Bill

A moment ago the Secretary of State referred to short-stay schools, which I assume will be taking over from the pupil referral units, for young people with difficulties who are not thriving in a mainstream school. They are termed ““short-stay schools””, but will he confirm that there will be no cap on a pupil's length of stay, so that they are not re-imposed on their mainstream school before they are ready or before they have made sufficient progress?