MATS pt 1, Section 2, Chapter 1 para 9.3.4
At aerodromes where taxiway stop-bars are used to protect taxiway routes andrunways from inadvertent incursions, controllers are not to clear aircraft to cross an illuminated stop-bar. Inoperable taxiway stop-bars and associated taxiways should be withdrawn from service and an alternative routeing used. The Aerodrome Authority may decide, on grounds of safety, that inoperable stop-bars and associated taxiways be withdrawn from service.
On the occasions when the withdrawal of inoperable stop-bars and associated
taxiways is not possible and the stop-bar cannot be readily suppressed, an aircraft may be cleared to cross such an illuminated taxiway stop-bar subject to the following conditions:
a) The stop-bar and aircraft affected are visible to the aerodrome controller.
b) The phraseology used is to leave the pilot in no doubt that the clearance applies only to the faulty stop-bar.
c) In the case of illuminated stop-bars protecting the runway, aircraft may not be cleared to cross without the assistance of an aerodrome operations vehicle.
NOTE: The requirement at a) above may be satisfied by the use of an SMR which has been approved by the CAA for this purpose.