Putting the Metro through Ranelagh on the planned route would be hugely divisive and controversial, a TD representing the area has warned.
Locals in the south Dublin village are angry the project will see the closure of the road at Dunville Avenue and the Beechwood Luas stop.
It has been estimated the cost of extra tunnelling to avoid the road closure at Ranelagh will be around €77m, while houses and a local cafe might also have to be demolished.
However, residents and politicians have begun campaigning to prevent the closure of the road that would be necessary under the plan to upgrade the Beechwood stop to Metro status.
"There is a lot of anger. Imagine if they close the road, there won't be that pedestrian access anymore," said Green Party leader and Dublin Bay South representative Eamon Ryan.
"How do you walk to the shops? How do you walk to school? It can't go ahead as is currently planned, I'm confident that it won't."
He believes the tunnel boring machine should "keep running," and the line be extended underground toward Tallaght.
"The Metro is a very different system to the Luas," he said, adding the plan to integrate the two systems posed difficulties in the south of the city.
Metro plans won't be ready until early in the New Year, as engineers attempt to resolve a raft of issues and concerns.
The problems highlighted following consultation with the public and interest groups have been the cause of the delay.
Engineers are now attempting to find fair solutions to the litany of concerns, including those raised in Ranelagh.
It's understood the extra time taken is to ensure there are solid answers to concerns.
Among the issues on the table is the impact the project will have upon are two schools on Mobhi Road in Glasnevin - Scoil Chaitriona and Scoil Mobhi.
Scoil Mobhi principal Marcella Nic Niallaigh has previously said "effective education" would be impossible with the diesel emissions, noise and vibrations that will come with the construction.
The 26km Metro line will travel between Swords and Sandyford and is projected to cost in the region of €3bn to construct.
The initial public consultation held by Transport Infrastructure Ireland was non-statutory and they intend on holding a second one after the revision.
NTA chief executive Anne Graham said the full length of the track should be operational by 2027 if it succeeds in the planning process.