Up to 100 people are expected to arrive at the Dáil this evening to express their anger at the building of the Poolbeg Incinerator.
Work on the €600m project in Dublin has started, seven years since planning permission was granted.
Frances Corr from Combined Residents Against Incineration says they are getting support from the whole city.
Ms Corr said: "We have huge support from the whole of Dublin city, but in particular from Clonfarf, Marino and the coastal areas, as they can actually see it as they look across the bay.
"They are just waking up to how large this is. Also, they've been looking at the whole issue of the traffic in and out and the hours that will be worked."
Impromptu anti-incinerator protest closes Kildare Street from Nasseau Street pic.twitter.com/IlmoI1pBSR— Micheal Mac Suibhne (@MicMacSuibh) October 22, 2014