The so-called Rossport Five have decided to cease their cooperation with the man appointed to mediate in their dispute with the global oil firm Shell.
The five Co Mayo men spent more than 90 days in prison last year for refusing to obey a court ruling ordering them not to obstruct work on the Corrib gas pipeline.
Former trade union official Peter Cassells was subsequently appointed by the Government as a mediator to oversee talks aimed at resolving the dispute.
However, the five men have now announced that they will no longer be meeting Mr Cassells in protest at alleged interference in the mediation process by Natural Resources Minister Noel Dempsey.
A spokesperson said the men were angry at this interference as they were led to believe that the mediation process would only involve Shell and the local community.