Unions have no where near the % memberships they used to have..agree corporates over paid but politicians arent overpaid when when compared to corporates imo
For example just universities for instance the vice chancellor is on average paid twice the amount of the PM...whos job do you think should be higher paid?
As to public sector wages that all depends, many public sector jobs have large vacancies ie police forces, if they were paid more and had better conditions they would have more staff...depends on how important you think things like policing, nurses and teachers are i guess
