Specialist P-way workers who use ultrasonic kit to check for cracked rails are employed by TubeLines but also provide the service to Metronet. That was, until Metronet got the hump about the prices TubeLines was charging them.
TubeLines ultrasonic staff then became much in demand with mysterious contractors, apparently trying to poach them.
The madness of the market, some might say. And further evidence that this task should be carried out by a unified, publicly-owned London Underground.
Meanwhile, though, union reps have rightly demanded a pay rise for these much-in-demand workers. So far, no deal has been done. Let's hope they are sticking out for a decent hike in wages.