MPs don’t get a big salary, historically large salary rises go down like a lead balloon, so they make their money up with expenses….and lobbyist money and “2nd jobs”.One interesting thing that came up on Question Time is that MP's can (and do) claim up to £3500 per year toward heating costs.
That went down well with the audience.
Although I’m no fan of Jeremy Corbyn, he has never taken freebies and thus can’t be bought…..so whether people like what he campaigns for or not, at least it is what he believes and not what a corporate donor wants (although he is still subject to pressure from Unions)