It will glow, dimly, due to the fact the ends of the tube are quite far apart and so they are at different potentials in the electrical field. It only really works where the phases are widely separated in space, such as the field of a high-voltage overhead transmission line. In a cable where live and neutral, or all three phases are present close together, there will be a lot of field cancellation which greatly reduces the effect. It would need to be a fairly high-voltage source, I doubt that it would work at 25kV, which most railway systems are - and, if it did, then you would probably have to be dangerously close for the effect to occur - with a high voltage field the gradient is sufficient at a much larger distance from the live conductor.
Standing under a transmission line and waving a long, pointed conductor at it is not something that should be recommended. I am not aware of anybody ever being zapped when doing this, but if it did happen then you would not get away with it..