So, in theory, I could be a non-UK/ROI national aware of this system and require entry to the UK without an immigration check. I say again, I have NEVER seen a clearly identified Police presence on the CTA Channel - only one airport official collecting boarding passes. I travel through here twice a month at the very least.
(i) book myself on a Ryanair Ireland-LGW flight and print the online Boarding Pass, tearing off the lower portion as though I have actually used it.
(ii) actually travel to LGW South on a flight from God knows where and hang around until the 'pretend' flight arrives from Ireland
(iii) go through the 'one man' channel, presenting my spurious Ryanair boarding pass, as no photo ID required.
(iv) Bingo - I'm in and completely under the radar. All the time smiling at the UK Border Agency staff turning back bona-fide UK passport holders because it's not their job to let them through if they've arrived from Ireland.
Doesn't it make you feel safe?!