"Climb FL XXX" means Climb FL XXX now?
For anotherthing and ATC'ers:
Somewhere in a previous incarnation, I remember the MAP (Manual of Air Traffic Procedures) and AIP (Aeronautical Information Publication) stating that a clearance to climb/descend must be initiated within one minute, unless the word "NOW" was also given, which meant (and still means) "NOW".
If ATC wants me to climb/descend, or turn/track direct to... "NOW", then they need to say "NOW" as part of the clearance.
Or is the UK ATC system have a peculiar idea of "NOW"?