If you're holding up traffic, as per the recent updates to the highway code, you should pull over and let people pass. Regardless if it's legal, if a driver is

If you're holding up traffic, as per the recent updates to the highway code, you should pull over and let people pass. Regardless if it's legal, if a driver is not driving at the maximum safe speed they can (which in an MOT'ed vehicle on a clear summer day on a straight and empty road should be the speed limit), they are either distracted, incompetent or they're not bothered about getting to their destination, and in all of those cases I would prefer if the drivers in question considered using a bus to fulfill their transportation needs.