Three carpenters are staging a protest in a 200 foot-high crane on the Balgaddy Road in Dublin today.
The three men, including a father and son, claim they were unfairly dismissed and are owed money by their employers.
The men have been in the crane since 8 a.m. this morning.
Gardaí have been called to the scene and the management of the Clondalkin site has stopped all work.
Mr Tom Fitzgerald of the Building and Allied Trades' Union (BATU), who spoke to the men earlier, said he could see "how workers are driven to this kind of action eight weeks before Christmas".
"The men have support from other workers at the site," Mr Fitzgerland added.
The carpenters said they refuse to come down until the matter has been resolved.
