In my new airline, we are allowed to take anyone we know and trust or collegues on the jumpseats (cabin or cockpit)
We are a European Carrier from a Shengen country and fly Boeing aircraft. This is how it should be with any airline.
The British overreact and are paranoid about what is really important about Aviation Security. And being paranoid is NEVER a good thing in our business.
CPML: You have my support, but I DO have to say that you must oblige by your operators rules to avoid after flight consequences I'm afraid.
HOWEVER: Bealzebub: During flight, the Flight-deck is under the Commanders authority and NOT under the companies! If you do not understand that, it is you who is not a captain in word, nor in deed. The captain allows in his/hers cockpit whoever he chooses whenever he is the commanding officer onboard. If these collide with rules and regulations, it will be dealt with after the captain finished his/hers duties and forseeks his/her command of the aircraft.