Transport spokesperson for the party Senator Kevin Humphreys said the project is "essential" for long term growth in Dublin.
Mr Humphreys said: "I am deeply concerned that Fine Gael and Fianna Fáil are colluding to ensure that Dublin does not receive the investment needed to address the infrastructural bottlenecks that are emerging in our capital city.
"In an attempt to spread investment to every village and parish it seems that the long needed DART interconnector tunnel will be scrapped for another decade.
"I am calling on those Fine Gael and Fianna Fáil TDs in Dublin and the surrounding region to commit to fighting to ensure the DART underground is a priority in the NDP.
"Abandoning the underground link as a fig leaf to rural TDs would be a mistake with long term repercussions for Dublin.
-- Advertisement --
"The proposed 7.6km underground line would connect Heuston station to the north-eastern rail line and provide for cross-city links between the south Kildare line, the Maynooth line, and the current DART services on the eastern seaboard.
"If the DART underground is left out of the capital plan, it could be after 2030 before it would be considered again. In the meantime Dublin will be left without an integrated urban rail system.
"Extending the DART to Drogheda is welcome and long overdue but it will result in the delivery of more passengers onto an already crowded line and the city centre stations. Building the interconnector alongside the extension would open up new capacity for commuters across the city.
"We keep being told that the National Development Plan will see an investment of over €100 billion over the next decade. The cost of the underground is estimated at €4 billion which is a fraction of the overall plan, and an essential piece of long term infrastructure. A project of this nature would also be an attractive proposal for outside investment and off balance sheet funding.
"The Government's mantra about the need for higher density in the Dublin region will be seriously undermined if it does not move to promote integrated rail transport. If we are serious about tackling climate change we should also be promoting integrated and sustainable public transport where it is needed.
"The Metro North link has already been committed to in the current capital plan with construction due to start in 2021 with completion by 2027. With that in mind it is essential now that momentum is maintained towards developing a 21st century transport system for Dublin. By ensuring both projects go ahead we have an opportunity to future proof our capital city."
(CD/LM)
