Andy Burnham's UK Home Office clarifies that dual British citizens must use their British passport and are not eligible for an ETA with another passport. What dual British citizens must knowThe update also confirmed that airlines carry responsibility for checking passengers' travel permissions before departure, meaning travellers who arrive at the gate without the correct documents risk being denied boarding. The Facebook post below has the update the UK Home Office sent to dual British citizens. If I wanted a Spanish passport i would have to surrender my British passport?" Us British citizens need one to enter the country, so why have dual citizens gotten away with it!"