"An EEA national must be admitted to the United Kingdom if he produces on arrival a valid national identity card or passport issued by an EEA State.", and in reg 13(1): "
"(b) a person working in the United Kingdom on or after1st January 2007 is legally working during any period in which he— (i) [does not apply] (ii) holds an accession worker authorisation document and is working in accordance with the conditions set out in that document;…."