i'm working class, female, ethnic migrant, northern,brought up in a densely asian-populated mill town, in a family that was even back then classed as living 'below the poverty line'. Had a free education at my local nursery/primary/junior/secondary/college - none of it was grammar or private. i'm as common as common is.....
Yet the first impression people get of me when i open my mouth is 'posh, rich, must have had a private education' 
I used to get picked on in school for the way i spoke and the vocabulary i used. Once i entered the adult world of employment etc i noticed that people made big assumptions about me....and once they got to know me they were very surprised to know my 'class' 
i was socially isolated as a child and growing up. i was only allowed to socialise at school/6th form college during school hours. i wasn't allowed to hang out with friends, play out after school, hang out with cousins etc. Luckily i was born with a love for reading and i'd devour any book i could get my hands on. i wasn't allowed to watch tv much, so the radio was my best friend - especially the talk shows.
So i believe that's where i got my 'accent' and vocabulary from. For me the way i speak is normal and has nothing to do with class/money.
Still tickles me every time people make the wrong assumption about me...and i still love playing along with it
i still love the shocked/surprised look on their faces when they realise i'm actually just 'one of them'
.
Saying that, i have noticed the positive discrimination-in my favour-based completely on the assumption that i must be middle/upper middle class. I think it's disgusting that this kind of discrimination still exists in our society.