Does anyone else present flights to the UKBA? Also if you do how does it work at your airport? Am just intreagued to find out! Is there some hidden legal requirement to present flights?
From memory, there is a legal requirement for the commander of the aircraft to "present" the passengers he has brought in to the UK to the UKBA (previously immigration). The commander is able to delagate this authority to a third party (this would be the handling agent which in your case local agreement has been reached with handlers and airport authority to ensure all flights presented irrespective of handling contract). In larger airports you may find this service is incorporated in to the airport fees and provided by an independant company.
I believe if there is no one to "present" passengers to the UKBA, and they want to stick to their protocol, they could insist that the commander of the aircraft comes and "presents" his passengers to them in the absence of someone nominated to do it on his behalf.