With regard to grammar school entry, year 8, the Code of Practice says:
Appeals following casual applications for grammar schools
3.38 Admission authorities for grammar schools are bound by the same duty as those for other maintained schools. This means that they must consider applications made at any time and if they refuse to admit the child, must offer the parent a right of appeal. See paragraph 4.1 for further appeals within the same academic year.
3.39 Some grammar schools do not offer a facility for testing applicants for admission outside the normal admissions round. In this situation, if the admission authority is not willing to accept that a casual applicant is of the required academic ability for admission, it should make arrangements for an appropriate assessment of the childâ€™s ability to be made if their parents lodge an appeal e.g. by obtaining information from the current or previous school. Otherwise, the panel must work on the assumption that the child is of the required academic standard, and follow the two-stage process described in paragraphs 3.1 to 3.7.
I agree with Sam's mum that you should check with the school what their policy is regarding previous qualification/re-testing.
As far as the Catholic school is concerned, I think it would be reasonable to explain why your son is so unhappy at the present school, but don't spend too long on this. If I were on the panel, I would be most interested in why he wants to come to this
school! It's an appeal for
a school, not an appeal against a school, so it's important to get the emphasis right. It doesn't matter if you repeat the case you made before.