Mayo Co Council has demanded that business people remove heavy steel gates from the two main entrances to Castlebar Industrial Estate, where there has been an illegal encampment of Travellers for a number of years, or face legal action.
The controversial gates, have been described as "a psychological nightmare" by the Mayo Travellers' Support Group (MTSG).
The gates were erected last month at key entry and exit points to the estate at Moneen which has been the home for years to a large population of Travellers in caravans.
In a statement, Castlebar Industrial Estate Development Group claimed that Mayo Co Council had resorted to "bully boy tactics" by threatening legal proceedings against business people who had worked tirelessly over the past 20 years to resolve serious health and safety issues on the estate.
It said that it is now apparent that these issues are not a priority.
The statement added that the development group, having exhausted all its efforts, would now be calling on the Minister or Ministers responsible to take urgent action to restore the estate to some form of normality where business people could operate without the threat of hindrance or intimidation.
A spokesperson for Mayo Co Council has confirmed that the industrialists had been advised that the gates were erected illegally and legal action would be undertaken if they were not removed promptly.
A spokeswoman for the Travellers' group has described the gates as "a psychological nightmare".
She asked: " What if there was a medical emergency and an ambulance was unable to enter the estate in the dead of night?"