A reliable source on another forum reports that Kemble now require hi-vis clothing to be worn airside by passengers and crew. An e-mail from Kemble Ops says:
Passengers are at all times to be escorted by the aircraft commander or crew member who is known to be competent to ensure his/her and the passengers safety. The wearing of high visibility clothing is mandatory.
Aircraft commanders or crew members, as applicable, are responsible for ensuring that a total ban on smoking whilst airside is observed.
The high visibility clothing rule applies to each person airside. One high visibility wearer in a group is non compliant and is not acceptable.
This will be in their AIP entry.
Time to send some e-mails of complaint?