Thanks for that Rats. neatly put. Whilst I am not bothered about using my passport on an internal journey, I am concerned that I am carrying a valuable document and risking it's theft when I could use a simpler document.
I have just applied for the photocard licence but have heard that they still send you back a piece of paper and that the plastic is not valid without the paper! I'll let you know as it sounds like a horribly British way to do things.
A national photocard would be a much better idea than a plan to ensure that we have not sold the internal ticket to a friend.
Security?? My Rats@rrse!!!