Manchester here. I work in a small primary school in a deprived area. We had our first confirmed positive case on Friday and sent a year group home.
Mitigation measures:
Hand washing when leaving or entering the classroom or before and after eating.
Children sitting in rows.
Doors and windows open.
Toilets, sinks and touch points cleaned every hour.
Tables cleaned in the morning, before and after lunch and at the end of the day.
Lunch in the classroom.
Staggered play times as well as staggered pick ups and drop offs at school with one way systems.
Parents to wear face coverings at drop off and pick ups.
Staff to wear a mask or visor when not in their classroom - no mixing of bubbles though.
Children to be isolated and sent home if presenting symptoms - only allowed to return with proof of confirmed negative test.
Despite all this now we have 1 confirmed case I suspect it will spread across the school like wildfire with siblings in different bubbles. In fact, it wouldn't at all surprise me if it was already endemic but we just don't know it.