The Prime Minister Jacinda Ardern says it was only yesterday that Transport Minister Phil Twyford realised he'd made a big mistake by making a phone call on board a plane. Mr Twyford offered to resign but Ms Ardern refused the offer. She did however strip him of his Civil Aviation Authority portfolio. Ms Ardern tells Guyon Espiner: "I cannot determine at the time if it was something obvious to [Twyford]. Either way, clearly the doors were closed."