As a non nats guy watching this argument it seems to me that 10% over three years looks pretty generous (as someone pointed out it's around double the inflation rate).
Also,didn't you all vote to accept privatisation three or four years ago? Surely (and apologies if that's not the case) it can't be too surprising that nats is now trying to 'trim' the pay/perks/staff in exactly the way several people warned they would when privatisation took place.
Welcome to the outside world.