Market forces.Experienced Approach Radar controllers are in increasingly short supply.About time Nats/Prospect thought about this.If another ATC supplier came over the horizon,then some might be tempted.NSL at the lower band units don't have a good record at fair treatment compared with NERL.Screw up the pension and a lot might walk even quicker.
Just remember market forces doesn't always mean a reduction in T&C.Look at the kicking the North Sea Divers gave that industry.