I really like these kind of actions
.
When in dire economic times, best thing to do is to bite the hand that feeds you
by striking thereby making the problem even worse.
Aking to railroad workers over here (all government workers btw) that go on strike whenever they want often unannounced and always at the busiest times.
I once asked them "why not work instead and not charge any fees for the travelling passengers, that'll really cost money for the employer, create sympathy from the public and doesn't inconveniance non affected parties ?, the logic of that question just was to hard to understand for those jokels.
Same could be done by the immigration officers @LHR, why not do your work
as usual, pick out those with immigration paper issues, process them as normal, for those that get cleared after being checked out or only have minor issues like lost passports that can be replaced etc... let them continue their journey.
For the ones that have real immigration issues, stop processing them, don't send them back to their countries ,don't fine the airlines as usual ,stop further processing and after a shortwhile police will have to intervene and find alternate housing for them
putting extra pressure on the government to solve the problem without inconveniancing the public and airlines too much.