The Government stat will always be the minimum BUT it better to have a minimum than companies rip off the worker, I know of a situation where by some if staff who worked for a company went sick they were told to take a days holiday, these poor working practices dont happen to the fortunate, they happen to the vunerable who usually have no Union protection or the required skills to work under better conditions.
The fact remains most employers will pay what they can get away with without Unions keeping them in check, terms and conditions of service will nearly always be far lower at a place where the Union is not welcome, there are exceptions, Google, Kelloggs (they have a Union in Trafford/Wrexham factories but not in the admin) , Lush and Zurich.