I am not sure whether it does include those doing passenger security
https://www.unitetheunion.org/news-e...-strike-action
Heathrow Airport Ltd (HAL) has ignored existing consultation procedures and has announced a fait accompli that workers in passenger services (who assist travellers to catch connecting flights), trolley operations, and campus security (the security guards who are responsible for all workers at Heathrow and vehicles being checked before entering Heathrow), will be outsourced by 1 June.