Todays YOUGOV poll
In the early 80s it was the working aspirational class of the South which drove Margaret Thatcher into downing street. It was the Basildon working class that kept John Major in and kept Labour out. It was that very same working class which turned to Blair in droves and gave him his landslide in 1997.
So when you look at the polls when it is split into class. Your ABC1 is split CON 35% LAB 38% LIBDEMS 13% UKIP 9%
When you look at the C2DE you see the big difference CON 19% LAB 49% UKIP 15% LIBDEMS 9%
This is the group which will win the General Election for Labour if it stays the same. But it is the section where would be Conservative voters who are still aspirational and don't wish to follow Labour are turning to UKIP.
Conservatives will always get the higher/middle class vote, But unless they do something to appeal to the working class and not squeeze the pips out of them, then the party is set for another stint on the opposition benches. Even tearing itself apart if some of it's MPs move over to UKIP.