Looks like the boys are required to wear ties, will the mother buck that too if her son decides he prefers a tee shirt?
We are all free to express our individuality, but not always using the method we'd prefer. As a kid it would have greatly suited me to start school at 10 am. The school system didn't see it that way. I adapted.
I come down on the side of the school. It's a private school. Their school, their rules. Disagree with their demands? Send your kids somewhere else.
Last I checked, England was a free country...
Having been a teacher is both public (state government run) and private schools I have a few thoughts about this situation.
The uniform he is wearing seems to indicate a private school that would be run by a board of governors. They set the tone of the school and use this as a selling point to attract clients. The parents and the school board enter into a voluntary contract with two way obligations.
The mother, having come up against a similar but reverse problem with her older son, should have known what to expect. In the photo the boy seems to be wearing the correct uniform but his hair is out of control. Hair like that should be covered as a hygiene measure and I shudder to think of him anywhere near a Bunsen burner in the science lab. Sikh boys have long hair but they wear it in a top knot on top of their heads and it is covered with a boys version of the adult turban. However, in the case of the Sikhs, it is a matter of religious observance. As adults they are also expected to never cut or shave the beard. It is an expectation, not a universal obligation for all Sikhs.
In his father's culture baby boys did not have a haircut before the age of three but this boy is a lot older than three. He has reached the age of reason. He needs to presented with a practical choice. School A is a good school but it has some rules you may not like. One of these rules is about how short/long a student's hair may be worn. There are also rules about clothing that must be worn and personal grooming - even if you want to you will not be allowed to wear nail varnish to school. You may have to study subjects that are not interesting to you.
There are other schools like School B, which is also a good school, where the rules are different. You may be allowed to keep your long hair but you will certainly be required to wear a hairnet in the workshop and kitchen and have it tied firmly back in the science lab. Sport and games will have special rules too. These rules apply to all students and you cannot expect them to always suit what you want. Whichever school you choose, you will have to follow their rules. If you decide that you want to never have a haircut it will be difficult but not impossible to find a school that allows you to do this but there may be other things you don't like. You may have trouble making friends but once you make your choice you will have to stick it out unto you do find one or two friends. You may not be happy for a long time but you cannot change your mind once you decide which school is best for you.
Which will it be - School A or School B? You decide.
If the boy is so attached to his hair that to have a haircut would be a traumatic experience I would think seriously about home schooling my son. He is too old to be having tantrums at the hairdresser. I would also seek the advice of a counsellor. He may need time to adjust to a culture where he is expected to fit in.
I know I sound hard but life is full of choices and compromises. It is a lesson that needs to be learned in childhood.