A Ramblers group is threatening to take court action against a water company it says has unlawfully blocked a footpath.
Members of the Ramblers in East Sussex said Southern Water fenced off the cliff-top path between Peacehaven and Brighton without authority for its Portobello pumping station works.
The group said the utility company has obstructed the path for more than 20 years.
Locals accepted the situation, but new research reveals the company did not receive permission for the closure, the Ramblers said.
A Sussex Ramblers spokesperson said: “As you walk along you will have a fine walk with open vistas of the sea, until that is you get to the Portobello site at Telscombe Tye.
“Here Southern Water have fenced off the path and dug parts of it up without any authority to do so.
“Many people did not complain because they were put off by signs displayed by Southern Water which said that there was no right of way. They thought that paths had been legally closed.”
Ramblers local footpath Secretary Peter Seed said: “We were very sad that the path was closed but we thought that the company had got permission to close it.
“But then research by David Brookshaw of the South Downs Society revealed that they had no such permission.”
The Rambles said East Sussex County Council, which is responsible for keeping footpaths open, has tried to negotiate with Southern Water and have even suggested a diversion to meet the company’s needs. But the company have ignored them, and despite upgrading work being finished, the path remains closed.
Ramblers area footpath secretary for East Sussex, Malcolm McDonnell said: “We have been very patient.
“But now work on the site has finished it is time for action so people can start enjoying the fine views and scenery along this stretch.
“I have written to Southern Water requiring them to open the path. If they do not, court action will be taken. Most ordinary landowners keep the paths on their land open. It is unfair to them if Southern Water do not.”
A spokesperson for the water company said: “Southern Water is committed to resolving this longstanding matter and is continuing its discussions with East Sussex County Council.
“The footpath cannot be reinstated along the original alignment, as a section of it is in mid-air due to the essential cliff excavation work carried out by the water authority in the early 1970s.
“This excavation took place when the present Portobello works were constructed, which was prior to Southern Water taking over the operation of this site. We will continue our discussions with the county council to secure a resolution.”