Thank you to everyone who sensibly and courteously answered the question without trying to turn it into a 'class-war' or posing their own straw man question just so they can pat themselves on the back for taking offence at a question I hadnt asked.
My suspicion was that the schools would be obliged to follow the guidelines because their insurance policies insisted on it or their insurance would be invalid, and therefore all independent schools would follow it unless they have negotiated alternative insurance (state schools are self-insured by council wide insurance not on a school by school basis) which is unlikely.
My DCs school has not made it clear that this is the case or that their options had been fully considered which I regard as a failing of communication on the schools behalf. If they had then there would be no need for to me to seek further information about similar schools.
So it is likely to be a commercial decision for the schools - not an educational one or a health one.
And to the the rest of the comments it doesnt seem worth responding to most of them frankly. Covid-19 is a real-world problem and solutions or mitigation will not be found in emotive and subjective language......there is no place in the debate for words like 'appropriate' which are meaningless and unquantifiable.
But in an effort to at least address some of them....
Deep breath......
Guidance is exactly that - advice. It has no basis in law and cannot be enforced. To those of you saying it is an obligation presumably you would also want to see prosecutions for people who dont eat 5 portions of fruit and veg a day as that is also government guidance.
State schools are beholden to their local council and ultimately the government, whereas private schools are beholden to the parents and owners and therefore make their own decisions provided it is not illegal.
It is not 'self-entitlement' to question, analyse and think for yourself. It is rational, logical and intelligent. Self-entitlement is believing that you should be allowed to do as you please irrespective of the reality of the situation and expect everyone else to do as you want as well......a good rule of thumb is anyone who flings out an accusation of 'self-entitlement' against someone is in fact the self-entitled one as they are complaining that the other person is thinking or behaving in a way that they dont like and should be prevented from doing so.
The point about the uproar if it was transmitted within the school because the school wasnt following guidelines is an interesting one. Its curious to know why this is the case (and I agree that there probably would be uproar) here and not for other more serious conditions - why do we not have these guidelines to in-school test for TB for example which is on the increase again?
The flip side of this is of course more serious for the independent sector. Imagine the Covid test being mandatory and a child testing positive forcing the child to self-isolate, along with their siblings and parents and as a result the family suffers a financial loss (maybe the parents business fails) and then it turns out that the test result was false (the PCR is unreliable and should only be used as part of a medical diagnosis) - would the family have a case for compensation against the school who administered the test? And the Liverpool results demonstrate that the Lateral Flow test is similarly flawed by giving excessive false negatives - imagine a child tests negative but is actually positive and is admitted to school. Would any victims of subsequent infection have a claim against the school for any financial or other loss?