Sharpshot is correct.
The primary task of any airfield/airport fire crew is to save lives, if necessary they will expend all their media (foam and power reserves) doing that.
The local authority fire sevice have the responsibility for preventing the consequences of any incident spreading any further.
This is where the airport
PR machine will go into overdrive as the industrial action draws nearer;
What every airport in the UK has failed to tell the travelling public is that without the local authority fire services, their is a very serious risk that the airport fire service would not be able to cope with a fire in a public area such as a large terminal building / cargo area/ fuel farm etc.
God forbid that it should happen, but .............