Abdul Hadi Pasha
Banned
Cornish has no native speakers - the last one died a couple hundred years ago. It may be taught at some schools, but any such attempt would be reviving the language rather than preserving it. The black country and Suffolk have dialects but these aren't distinct enough to have separate classes in them. Even Scots is probably not distinct enough for that, although it is barely intelligible from English.
EDIT: Just checked Wiki, and the UK actually has no de jure official language. Cornish on the other hand is recognised as a official UK minority language.
I don't think that having a single language of education is the same thing as oppressing a minority. Given that contrary to general opinion, and I don't know how many times I have to say it, that the Kurds and Turks are intermixed throughout Turkey, it would be difficult to offer parallel school systems, and that would just lead to apartheid. A large percentage (as many as a third) of Turkish Kurds live in Istanbul. What do you do? Bus all the Kurds to a separate school?