The simple answer is: it depends which one.
Taking the examples you’ve cited:
For all his many manifest faults, Johnson has charisma and well developed social skills which I expect he enjoys exercising with people from all sorts of social backgrounds. I think if he despised working class people per se he would not be able to do that to such effect. I also think his narcissism is such that he views his man of the people skills as being central to his appeal and he will therefore take particular gratification from connecting with working class people. So I don’t think he hates them, no.
Rees-Mogg will despise the working class, or at very least view them with complete contempt, which surely amounts to the same thing.
Also, there will be plenty of public school educated politicians who will view everyone the same. Tony Benn certainly didn’t look down his nose at the working classes. Nor did Tony Blair.