Mayo TD, Rose Conway-Walsh, has said the re-opening of the Western Rail Corridor remains a key priority for Sinn Féin.
Speaking after the EY Report was published, Teachta Dala Conway-Walsh said: "The failure of the EY Report to evaluate the strategic importance and the wider economic benefits of the WRC is alarming.
"This, combined with numerous technical inaccuracies, simply means that to use this report for political decision making would be reckless.
"The government has given a commitment to address regional imbalance and achieve net zero carbon emissions by 2050. Minister Ryan has publicly expressed his commitment to the reopening of the Western Rail Corridor.
"He received cross party support from the vast majority of Western Oireachtas Members for this commitment. I am now asking him to keep his word and work with us to deliver this key transport infrastructure.
"It is time to stand up and stand together for the West. We can no longer afford to be controlled and constrained by a cost benefit analysis criteria that mitigates against the West.
"I raised this issue with An Taoiseach a number of weeks ago and asked him for a review of the appraisal processes used in decision making, to ensure better balanced regional development and greater transparency. It is precisely because of reports like this that we need such a review to enable people to live and work in Rural Ireland.
"Investment decisions must be guided by clear strategic objectives giving weight to factors that can bring transformational change. We need to move away from decision-making by audit companies who do not have skin in the game."
In a recent Dáil speech, Teachta Dala Conway-Walsh stated: "Relying wholly on analysis from auditors using narrow monetary measures, often based on population, rather than the transformational change that is required, impedes potential growth.
"Too often projects such as the reopening of the Western Rail Corridor are dismissed or delayed for years, even decades. We have huge opportunities for growth potential in the green economy along the western seaboard.
"We must maximise the potential of the Atlantic Economic Corridor with sustainable investment in the Western Rail Corridor, Ireland West Airport, telecommunications, roads and education infrastructure. The fight for the reopening of the Western Rail Corridor is only ramping up," she said.