Britain is now more or less a classless society
You cannot possibly argue that point, not only does the UK still have a class structure, it also has a caste structure than Europeans are completely blind to. Not only that but we have an increasingly sectarian population. The North South divide is still very evident. it is not as simple to talk about working class, middle class, upper class, Aristocracy etc. the subdivisions, subsets, subcultures within the UKs increasingly diversified nation all contribute to Class Structure.
Britain is well on its way to becoming a society run by the wealthy for the wealthy and so is Poland.
Er...it always has been, as is the rest of the world.
You could well argue that the working class in Britian has been destroyed, that is a feasible argument.