The UK does not have an official language.
De jure, Wales does
Cambridge Dictionary defines official language as:
> the language or one of the languages that is accepted by a country's government, is taught in schools, used in the courts of law, etc.
There is no debate whatsoever that English meets that criteria in the UK
What's your argument there?
Though now we’re just descending in to semantics which is not very entertaining
Indeed, there’s even no official version of English unlike, say, French and Dutch.