I guess some of these popular crossbreeds could become recognised in time.It would take a good few years of Sprocker v Sprocker, Cockerpoo v Cockerpoo and similar. I imagine The Kennel Club and breeders would have to be sure the new breed was free of any inherited defects from original cross. All pedigree dogs have come from cross breeding at some earlier stage.
That's because like other 'designer' dogs they're mongrels and not a pure breed
Hmm, two descriptive words there I don't care for, 'designer' sounds snobby while 'mongrel' feels like the other extreme, a scruffy unkempt mutt. I suppose Hartley does look a bit unkempt at times, but I think 'cross-breed' is the nicest description.