GoneWest,
The dispute you describe at MAN was the Airport Firefighter, who walked out. As there was no fire cover at the airport, it became unlicensed, hence no commercial movements. Airport firefighters are normally employed by the Airport Authority or by a contractor operating on behalf of the Authority, therefore they are not involved in this dispute.
ATCbabe,
The airport fire category is defined solely by the personnel, equipment etc directly available to the Airport fire service themselves. The Merseyside fire brigade held a series of strikes last year and apart from not being able to use the direct line to the LFB (because they were not there) and having to use a special number to 'Green Goddes HQ', the effect on LJLA was sweet FA.