Work has started on a MetroLink station in Dublin, despite planning permission for the rail line having yet to be lodged.
Construction on the terminus at Charlemont, which currently serves the Luas Green Line, started last year.
Planning permission for the MetroLink, running from Swords to the city centre via Dublin Airport, is expected to be lodged this year.
But the Irish Times reports construction works, costing some €12.5m, have already gone ahead to allow an underground station at Charlemont near Ranelagh.
Local residents groups claim authorities are preempting the planning process and locking in the route for the line.
Ciarán Black, of the Charlemont/Dartmouth Community Group, told Newstalk Breakfast the location is wrong.
"What's happening is the NTA are pushing ahead with a terminus location that's highly controversial.
"And they're doing so before it's even been signed off by Government.
"One of our key issues we want to raise is that I think most people on the southside probably don't realise the implications of this location.
"It's just simply not a terminus at all... from the NTA's own words there'll be no drop-off location, there'll be no taxi rank drop-off.
"There'll be no parking, it'll be for residential only.
"And the only way of access Metro is through a very difficult interchange with the Green Line Luas.
"You'd have to get off above the canal - if people are familiar with the current Charlemont station - above the canal, down on to road level, walk along the road and then down into a deep station underneath.
"That's the best possible outcome that the NTA have come up with".
He says the issue with Dublin's planned MetroLink is that it still has to be accessed via a central point.
"Cities that have Metros around the world generally have a kind of a north-south spine, and that means you can access it from multiple points relatively easily.
"The problem that we have in Dublin is... a Metro that goes from Swords through the airport to the city centre.
"And for the next number of decades, we're going to have to access it at a central point.
"That means we need a terminus that is easy to access for multi-modes of transport - unfortunately we don't have a spine that goes all the way through."
He adds: "The solution is, rather than trying to put it in a place that's got a really restricted access, is to put it in the most obvious place: Stephen's Green".