What Does Class Mean?

It is sometimes suggested that class has now become entirely divorced from party allegiance in the UK.  This statement is based on the 2017 General Election voting figures which do indeed show at best a weak relationship. 

The trouble is that "class" has always been a slippery concept.  In the days of Attlee I think it usually referred to your type of work with manual labour being at the bottom of a ladder and professional qualifications (say, lawyers) at the top.  A more modern take focuses on the standard of living, although this seems to ignore changes in expectations e.g. the proliferation of white goods since 1945.  I recall one critique put out by an extremely Corbynista MP seeming to argue that no one who was elected prior to 2015 could be counted as working class, which I find rather startling.  Mary Creagh MP once complained that some people regarded her as posh simply because she uses received pronunciation (if that is what it is still called.  Certainly in Scotland an anglicized accent can be a signifier of class. 

It seems class is now so differently defined that it is no longer a useful tool for categorising people.