Tried to look at ANO Schedule !0 last night, but it has been deleted and replaced by CAP744. Lots of information, but it does say……
"The Aerodrome Radar Control endorsement shall not permit the aerodrome controller to use the surveillance radar equipment in any way that will detract from the primary task of providing an aerodrome control service by visual observation of aerodrome traffic".
Sorry Guv', I didn't see the vehicle stray on to the runway/Aerodrome Ground Incident*, I was too busy vectoring a few inbounds.
*delete as applicable