The Bray to Greystones cliff walk is expected to be closed for another three years, according to Wicklow County Council.
The walk has been closed for nearly five years due to a number of landslides which have left some parts of the seven-kilometre route unstable.
Peter Murtagh is a member of the Friends of the Cliff Walk Steering Group.
He said they were surprised, depressed, angry and dismayed, as many people in the community are.
Mr Murtagh said when they began this week, they were looking back on five years of closure, five years of doing nothing and five years of failure.
"We had a meeting with councillors and other community representatives at what was supposed to be a fresh start to put those five years behind us, and it looks as though we're now looking into possibly another five years," he said on RTÉ's News at One.
"The best estimate from the expert engineers contracted by the Council RPS Group, who gave a very detailed briefing to the meeting is that it will take, at the best case scenario, another three years and realistically you can add another two to that.
"We're looking at a decade lost with catastrophic consequences to local businesses," he added.
