Errmmm...just being devils advocate here.
But with all this harping on about 'thats why we have such a great safety record' stuff in oz/nz. I just don't really seem how it can be linked to cabin crew ratios if the safety record over there is so good that crashes never really happen. I'd say that might be down more to the pilots/maitenence/ATC. And perhaps the fact (that in Air NZ case anyway) the fleet size is very small on a worldwide scale and flying into/through less congested airspace than the average euro/US airline.
And surely operating rotations like LAX/JFK/LAX (per QF) is more of a safety hazard from a cabin crew perspective than a 1:50 ratio?
In the UK as has already been pointed out the legal minimum is one crew member per 36 pax seats.
At BA we rarely operate to the legal minimum. Tho the times they are a changin (especially for the poor buggers on s/haul). This however is totally service driven and got nothing to do with safety.
On short-haul (A319/320/321/757/767) the crew ratio is dependent on the Club (Business Class) loads.
On L/H our crew compliments are fixed. 8 on the 767 (also legal minimum - but only 181 seats on it). 12 or 13 on the 777 (route/config dependant). 15 or 16 on the 747 (route/config dependant).
In regards to service levels.....when I came home to OZ a few months ago and flew QF from SYD to MEL to see my sis couldn't believe what you guys offer on the aircraft on such a short flight. Was impressed!!!