Attempts to ease traffic congestion at Swan Brae in Methil has made the problem worse, claim local residents.
In a bid to stop an influx of BiFab workers parking on streets near Fife Energy Park, double yellow lines were painted on the road last month.
However, according to campaigners at Memorial Court, tensions between long-suffering residents and workers are at an all-time high.
A spokesman said: “On two separate occasions a BiFab employee has urinated in our car park in full view of all.
“The litter accumulating in our car park - and surrounding areas - is disgusting and nothing is being done.
“Enforcement officers are barely seen and on a nightly basis, 28 to 30 cars continue to be parked illegally. We’ve decided a barrier and fobs for residents ought to be installed with immediate effect.”
BiFab has a contractor on site preparing some land for extra parking spaces.
Meanwhile, David Paterson, Levenmouth area service manager, said Swan Brae congestion, while “not perfect,” was better.
He added: “Enforcement staff are out within working hours but obviously they are not there at two or three in the morning.”
Mr Paterson also said he was aware of more workers trying to use the residents’ car park at Memorial Court.
“We are saying to residents that if they experience an incident which is car-related, take the number of the perpetrator’s vehicle and phone the police. We know it’s difficult for people but to try and nip behaviour like this in the bud is the best approach.
He concluded: “We all want BiFab to be busy and prosperous but it needs the infrastructure to meet the demands of its workforce.”