TBH I don't see much difference between criticising Rees Mogg for his very posh accent, BJ for his inability to utter a coherent sentence and AR, who in parliament uses overly informal language (quids, scumbags) to me they all come under the heading of "could do better". As a Brum, I know how a strong Birmingham accent is perceived by some people and there are other accents that are equally prejudicial, so for anyone in the public arena, I'd say tone down the accent and don't use slang otherwise some people will only hear that rather than your message. fwiw in KS2 English, children are taught this!
National treasures. Who would you choose?


