Stansted?
Based on the Air UK 146 alone
Belfast also has the green vehicles which I think are indicative of 'Servisair' Ground Handling agents, previously light blue.
AL1 It is Aviance and they cover te following airorts:
Aberdeen
Birmingham
Cardiff
Edinburgh
Glasgow
Jersey
Leeds Bradford
London Gatwick
London Heathrow
London Stansted
Manchester
Southampton
Teesside
Luton
So I will stick with Stansted and if not, Belguim - Brussels