Somebody asked for a definitive answer - well, the Manual of Air Traffic Services Part 1 - Section 2 Chapter 1 Page 7 Para 10.3.4 is quite clear about this. Sorry for the long quote -
"At aerodoromes where taxiway stop-bars are used to protect taxiway routes and runways from inadvertent incursions controllers are not to clear aircraft to cross an illuminated stop-bar. The inoperable stop-bar and its associated taxiway should be withdrawn from service and an alternative routeing used. On the occasions when this is not possible an aircraft may be cleared to cross such an illuminated taxiway stop-bar subject to the following conditions:
a) The stop-bar cannot be suppressed;
b) The stop-bar and aircraft affected are visible to the aerodrome controller;
c) The phraseology used is to leave the pilot in no doubt that the clearance applies only to the faulty stop-bar;
BUT (my but!)
d) 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."
So according to the book, you pilots should never be told to cross a red stop-bar protecting a runway without being escorted by an operations vehicle.