I was hailed in the queue by a fellow passenger, an Ulsterman living in Slough, who recognised me from my BBC election broadcasts. He was returning to England with his Ugandan wife from Christmas with her family. It seems that there is no longer a direct flight from Heathrow to Entebbe (which I find extraordinary) so the best way is to take the Brussels flight that starts in Kigali and takes on more passengers after a short hop east.
We chatted about Northern Irish politics (I imagine he doesn't find many fellow enthusiasts for that subject in Slough, let alone Uganda) and then parted company as we boarded; he had to wait for the rest of his family to get through. At the end of the short flight, we were told that the UK Border Agency would be waiting for us at the door and would check every passenger's passport as we disembarked. They did not check mine, and it was fairly obvious why not.