Dublin city councillors have voted overwhelmingly against the Poolbeg incinerator project.
The councillors voted 52 to two against going ahead with the plan.
Dún Laoghaire-Rathdown councillors also opposed it but Fingal voted in favour.
However, the final decision will be made by the chief executives of the four local authorities.
A special meeting of Dublin city councillors this evening was told that motions have been passed opposing the Poolbeg incinerator on 30 occasions but the power to decide is not in their hands.
Many councillors expressed the view that the incinerator is too big and there also concerns about the impact locally.
But council officials said there is more than enough refuse being generated in the Leinster region to make the 550,000 tonne facility viable.
The council's Chief Executive, Owen Keegan, said he could not release financial details of the deal with private partners Covanta because of commercial sensitivity.
However, he pointed out that the plan had been passed after vetting by the National Finance Development Authority.
It is expected that the chief executives of all councils in Dublin will give the final go ahead within weeks.