Unfortunately (or fortunately, depending on your viewpoint), all public sector jobs are 'banded', meaning that the skill set, etc for those jobs is assessed, the likely qualifications and intelligence needed assessed, and the job thus allocated to a band, which can NOT be deviated from.
This is useful in normal times, in that you can't get people/departments wanting pay rises, and threatening to quit if they don't get them - the simple fact of the matter is that the job is a fixed band, and apart from normal pay rises and the stepping up within that band (you start on the bottom pay and work your way up to the top over 3-5 years), that can't be changed.
At present, this is causing problems in some cases - for example, in the NHS, a HCS (health Courier Service) driver (driving vans, delivering / collecting samples to labs, patient notes, stock deliveries) is a band 2. Which pays less than £20k per annum. A HGV driver in the NHS is band 3, which caps out at under £22k per annum. So the NHS is struggling with staff retention in those areas, but they can't get round it by offering higher wages - the banding is set in law.
So this is normally a good thing, in that it prevents localised wage inflation, and the unions agreed to the banding, so people can't bargain wages up. But sometimes it means that public bodies can't get staff when there is this wage price inflation in the wider economy, or the wages they are offering look a lot lower than is otherwise available.
But, do bear in mind that there is also generous annual leave entitlement that isn't listed in that salary, along with a reasonable pension package, and if the person has to work unsociable/weekend hours then they are are paid quite generously too - myself in the NHS, I get 30 days annual leave PLUS bank holidays, and if I have to work a Sunday then I get paid at 1.83 x my normal hourly rate (that 'bonus' rate is only paid at the lower pay bands, the higher up you go the less it is, for higher bands it's 1.6 x). (My Saturday/night time rate is 1.41 x normal pay, for more senior staff it's 1.3 x)
The headline salary looks relatively poor. But it isn't the whole picture by a long shot (excuse the pun)
aye, I get what you’re saying. But just for continuation sake, if you work a bank holiday, you get paid double time, but no day back. If you are a scheduled rest day on a bank holiday, you will get a rest day in lieu put in your “pot”. 
