I was flying out of LHR on Sunday and we had a delay because of a storm around STN, that airport was closed and all incoming traffic was on hold around London so all outbounds from LHR were delayed by an avrg of 45min because of traffic enroute... your delay was way too long, so I doubt it was for a similar reason. maybe some tech issue? A3 should tell you
i didnt hear about any strikes planned for yesterday