More than 1,200 residents in Dublin's North Strand and East Wall areas have vowed to barricade all access routes to a local railway bridge if Iarnród Eireann makes any attempt to start work on replacing the bridge.
The North Strand Community Action Group has also called on the Minister for Public Enterprise, Ms O'Rourke, to justify Iarnród's contention that the replacement of the bridge at East Wall Road is exempt from planning permission.
Work on the €20 million project, scheduled to begin next weekend and last until October, involves 598 hours of digging and drilling during the night and at weekends to erect a new bridge, including an additional railway track.
Local people are particularly angry about the proposed installation of a six-metre (20ft) high wall, fearing that it would put many residential properties along Stoney Road, Leinster Avenue and Leinster Street East "into permanent darkness".
The community action group is calling on the Taoiseach, Mr Ahern, who represents the area, to call a halt to the project "until it is subjected to the full rigours of the democratic planning process" because of its scale and the disruption involved.
A spokeswoman for the group, Ms Fiona Moloney, said all residents were united in their stance to block any work on the site until Iarnród Eireann agreed either to scale down the development or apply for planning permission.
The group is meeting the chairman of CIE, Dr John Lynch, today to seek a commitment that work will not start on the site until a compromise is reached. "Failing this, all access routes will be blocked by residents", Ms Moloney warned.
She said local people were "outraged by the way in which Iarnród Eireann is bulldozing its way through a residential area". The company had not even carried out an environmental impact study, despite the proximity of the project to houses in the area.
Iarnród claims it is exempt from planning permission because the development "does not materially affect the external appearance of the structure", and this opinion has been accepted by Dublin City Council.
The company has also described East Wall Road bridge as "the most struck bridge in the country" by juggernaut trucks, suffering 104 "strikes" since 1985, of which 53 occurred since 1998, and it needed to be replaced primarily for safety reasons.
But the community action group says the real purpose is to provide an additional rail track and to build a new bridge with a higher clearance for juggernauts that won't fit into the Dublin Port Tunnel.
Iarnród Éireann denied this charge. "The major benefit of the project is clearly a safety one, ensuring the safety of rail traffic over this key artery carrying northside DART services, Drogheda/Dundalk suburban services and the Dublin-Belfast Enterprise".