I thought that it was possible to travel in the EU with a national identity card rather than a passport. However, some friends in Denmark say that is no longer true and they need a full passport even to go to Sweden. Is this so? I have not heard it from other sources.
I had just started to travel in the EU with my Irish passport card and I have had no serious problem yet. I even went to Denmark with it but since I changed planes in Amsterdam, I did not need to show it in Copenhagen.