To have a student learning in one class then teaching the next is completely unacceptable, especially when there is no shortage of qualified supply teachers that can fill this role. If a school is unhappy with their current supply teacher provider there is plenty of opportunity to find a quality alternative due to the highly competitive nature of the supply teaching market.
There is simply no logic in using students to teach other students. Not only will a student not have the correct qualifications and teaching experience; they also won't have gone through the appropriate background checks required from teaching staff, and so could actually pose a risk to children. If schools want to increase their chances of getting the teacher they want, they should look for agencies accredited with government-recognised initiatives, such as the Quality Mark scheme, to ensure their students get the quality of teaching they deserve rather than leaving their education to chance.
John Dunn, Chair of the Recruitment and Employment Confederation's education sector group: Select Education Plc, Luton.