englishal and PPRuNe Dispatcher,
There would be no problem if A/G operators did what they were supposed to do and no more. Why can't they? It's all written down clearly. It's not rocket science, and it's not complicated.
At one point I started training to be an A/G operator at Sleap. The first day the chap who was teaching me was quite specific - never use the word clear, don't say "at your discretion" (only FISOs are supposed to do that, I think), just give runway in use, QFE, QNH, and wind info and similar. If asked for traffic info say something to the effect that there was traffic in the circuit and coming and going and they should keep a good lookout. Not difficult is it?
Right, the second time I had another guy. He cleared people to taxi, asked them to hold, gave them circuit instructions and so on. When I pointed out that this was illegal he just got annoyed; he'd been doing the job for 16 years and wasn't about to change for a new trainee A/G operator. He made me do as he said, but it was the last time. I never went back.
Why is he allowed to carry on? I don't know for sure, and it's another story anyway. But people like that shouldn't be allowed to. Apart from being illegal, they confuse pilots, and that could be dangerous.