I went to Oxford university in the 90s from a state comp in the home counties. I had never really met anyone who had a different accent from my own so (like many people, I now know), assumed I had ‘no accent’. As soon as I arrived there, I was ridiculed for my accent and told I was an ‘Essex girl’ by my mainly middle class privately and grammar-educated peers (actually I spoke something like Estuary English, I guess). I remember sitting next to a professor one evening who expressed amazement to meet someone with a regional southern accent at dinner. I was told that it was sad that I sounded so awful in English while my French accent was beautiful (I was studying languages). This deeply affected me and I gradually began cleansing my speech and assimilating. It makes me sad that I felt that I had to do that. I now sound just like those people who ridiculed me. I had a couple of friends (also from comps), who did not lose their regional accents and continued to be victimised. Interestingly, it seemed to be better for people with Welsh or Scottish accents which were somehow classless.
Mine started a long time ago. When I started at Oxford in the late 80s someone told me, ‘You can’t possibly be studying English at Oxford with an accent like that!’ This came hot on the heels of a teacher at a study week telling me ‘The northern accent is generally associated with being thick.’ I now teach on the outskirts of Birmingham and it’s lovely listening to some of my A level language students who are really proud of their accent despite the prejudice they encounter. Same kind of things I was getting back then.