AFIAK, if you have concerns about a secondary school breaking their risk assessment, you can report to the local authority. Or so I have been told re another local school.
We have been told we can circulate the room if we wear a mask. I don't know if that's an option/allowed in other schools- but honestly I think it's probably as safe as standing at the front with 30 kids breathing towards you for 50-75 minutes.
There's maybe two rooms I teach in where the 2m distance is genuinely possible. For context, I teach in 11 different rooms if we count tutor time. Even in one of the rooms where 2m distancing is possible, it isn't really because the students have to come very close to my "area" to leave/enter the room (albeit this is usually brief). It's hard to explain, but it's a science lab with a weird layout. The ventilation in there is also crap.
In some, 1m distance isn't possible. In one of these rooms, I rearranged the desks to create more space, but they were back literally 1m from the front wall of the classroom by the next week. If a child in the front row of that class gets ill, I'm not going to say I was always 2m away.
I also do 4 duties a week where it is impossible to distance. Some, but not all, of these are outside though. In the corridors, distance also isn't being maintained, and in some cases, there are crossovers between year groups too, but no-one is interested in this. I've tried to raise issues via the relevant SLT people, but they aren't interested, so now everything is just going to my union rep.
It should be everyone's concern, because it will be teachers passing it between bubbles that makes children ill and at the very least inconveniences families. But schools can't stay open with too many teachers off.