I think I am a working class. Although having an above average salary at still a reasonably youngish age (27), so does my wife, 1 kid now and if we both continue to work we would be fine and hopefully wecould get our 1st property on a mortgage by year end or beginning of next year. (and thats after years of savings and getting my own deposits) But if one of us get the sack, things will get tight at home. and pocket money to both parties' parents (one retired and dad semi retired) will need to cut short. and whoever gets the sack will need to find a new job quick before things turn more difficult.
I think for someone to be in the mid - upper class they will need to have a weathy backer, ie. mum and dad. The one who could ask dad to lend a few grand for getting a deposits on their first property, the one who may get fired tomorrow at work, but their parents will tell them to come and stay at their 3-4 bedrooms house for a while and take your time to find a right job, or even daddy asking friends if they may have job offers for their son/daughter. The one who could ask mum to buy her wedding dress etc.
Just my classifications though.