The cost of constructing the proposed MetroLink between Dublin Airport and the city centre will be much higher than a Luas line extension, according to a policy consultant.
This comes after the Committee of Public Accounts (PAC) revealed on Monday that €300 million has already been spent on the MetroLink, despite no construction having yet taken place.
David Geary, consultant in European law and policy, tweeted dissatisfaction at plans to go ahead with MetroLink construction at a higher cost than necessary to the tax payer.
"We could connect the city, North Dublin and the Airport with a Luas for a fraction of the cost of the MetroLink while we wait for it to arrive," he said.
Read More: Planning permission for Dublin's MetroLink set to be lodged in September
The idea of a Metro system in Dublin was first floated in the Platform for Change strategy published by PAC in 2000 which estimated that a metro system would be operational by 2010.
Speaking of his own proposal on The Hard Shoulder, Geary said that is essentially looks to "extend the Luas line from the Broadstone/DIT stop out to the airport along the Ballymun Road" which would "extend the Luas service to Drumcondra, Glasnevin, DCU, Santry and Ballymun."
He also highlighted the expected construction timeline of MetroLink in an interview with Newstalk earlier in the week as a negative element of the Metro project.
Initially proposed in 2015, he stated that it could take up to 10 years to finish versus the Luas extension which he says could be completed in 7 or 8.
Comparing the Luas with MetroLink as the ideal solution to connect the city centre with the Airport, Geary said: "It's 5% to 10% of the cost of what the Metro might cost, and small change in terms of what the cost overruns to the Metro are likely to be."
Brian Caulfield, Professor of Transportation at the School of Engineering at Trinity College Dublin, spoke to Newstalk of the €300 million pre-construction costs of MetroLink to date: "I suppose when you look at the overall capital cost of the project, it's expected to be between €9 and €12 billion, so €300 million is almost like small change when it comes to the overall cost of the project."
Planning permission for Dublin's original metro plan, Metro North, was granted in 2011 but was subsequently scrapped by the Government due to the recession, and Caulfield regrets this decision as tarnishing the image of Dublin abroad.
"If we had gone with even the original 2011 planning permission, I would argue that we would be starting to talk about the next line," he said of Dublin's transport infrastructure.
"It sticks out like a sore thumb across Europe in terms of cities that are connected by rail to the airport."
