I work in a primary school, teaching a class in the morning for two-and-half hours and another in the afternoon for the same time, with an hour's lunch break in-between. There is no non-contact time. I use my lunch hour to see parents and do other tasks as well as eat. The head has decided that from this month the lunch break will be 40 minutes and that we have to supervise children for the other 20 minutes. I will not be paid for this and will have no other break. Is the head allowed to enforce it?
The lunch break issue was decided many years ago. Teachers are entitled to a break of "a reasonable length" either between school sessions or between 12 noon and 2pm. I am not sure that reasonable length has been decided officially, but 40 minutes seems long enough. It may not be long enough for a break plus all the other tasks that teachers try to cram into it. No teacher may be required to undertake midday supervision during this period.
If all children are in the classrooms and are required to be there even if they leave the premises at lunchtime, it would seem the afternoon session has started. If not, and it is part of lunchtime, no teacher may be required to undertake supervision during this break.
If it is part of the afternoon session, it will be paid work. I suggest that the teacher governor raises these issues at the next meeting. You should qualify for non-contact time on a pro-rata basis once it is introduced under the workload agreement.