Originally Posted by
22wingit
As far as I have been able to determine, EU governments seem to leave these policies up the the airlines' discretion.
I don't believe that's the case. As far as i'm aware, the CAA (UK's version of the FAA) mandates that under 2's must be secured using an infant seatbelt (loop that attaches onto the parent's belt).
Rules re: use of carseats do seem a little more airline-specific, but again for UK carriers the rule is that if the seatbelt sign is on, Jr must be in your lap using the lap belt.