Many years ago I was co-pilot of a flt divertrd from Luton to Heathrow. The ramp agent informed us that with a lot of diversions it would be hours before the bags would be unloaded. Captain turned to me and said "We could make a start, are you game for it?" Before I could say anything, the rampie said "If you touch a bag, the baggage handler's union will black the aircraft, and it will be here for a week.". We headed for our taxi back to base.
Years later I was a captain with Ryanair during the handler's strike, and as Viking said, saw M O'L loading bags with half the office staff of Ryanair.