A Fine Gael Senator says she cannot see any reason to delay the Metro North project out to 2034.
Local representatives in Dublin and campaigners are demanding the Government sets out the plans for DART+ and Metro North.
It follows reports the projects could be delayed for a number of years.
They were due to be completed by 2027, but now may not be ready until between 2032 to 2034.
The plan was first officially announced and financed in the 'Transport 2021' plan back in 2005.
Senator Regina Doherty told Lunchtime Live the timeline should not be pushed out.
"It's 30 years ago: there are people who are living in Swords - all along the tracks right up to Dublin North in Balbriggan - who bought their houses or apartments with Metro North as part of their sales brochure.
"And here we are now, finding from a leak yesterday in the Mail on Sunday, that this project is not going to be delivered until 2034.
"And it's not acceptable".
And she says while the plan was initially delayed during the economic downturn in 2008/2009, there is no excuse now.
"There's absolutely no reason that would be acceptable for this project - which is going to be seismic in the changes that it will make - not just for public transport, for the response to climate change which is immediate and needed now to the people of Dublin North.
"I can't see any reason that would be acceptable to delay the commencement of this project to 2027 and its completion to 2034".
'We need clarity from the Minister'
Senator Doherty says the first she heard of this was the leak in the tabloid newspaper - and that the priorities need to change.
"All of us as Oireachtas members receive regular briefings - I was at a briefing only last week around the ambient structures that are going to accompany the likes of BusConnects and Metro North.
"Not everybody was welcoming Metro North, people did have concerns around parks and walkways and train stations etc - and all of those have been responded to.
"And now we find that we're not even going to put a shovel in the ground until 2027?
"What in the name of God are we talking about parks for if we've got specific problems around putting boots on the ground until 2027?"
Senator Doherty says she emailed Transport Minister Eamon Ryan on Sunday for clarity.
"What we need now is clarity from the Minister... I emailed him yesterday.
"So not only am I looking for a public statement, I'm looking for a meeting with all of the Oireachtas members on behalf of the citizens who this is going to affect to make sure that we can ensure that it either stays on track - or if there are issues, that we tease through those issues to get it back on track".