Whilst I don't doubt the points above, the question is presumably one of why do 20+ people need to make this route on a daily basis.
IIRC, the best part of 20 years ago Ford had a BBJ style thing that flew from Stansted to Detroit six times a week, and GM had something similar out of Germany. However they found eventually that it was a needless extravagance - the flights were full because they were there, not because people needed to travel!