Figures by the Department of Finance on a disorderly Brexit "may be conservative" according to Minister Paschal Donohoe.
The initial assessment by the Department suggest that the level of economic activity will be around 4¼ percentage points lower over the medium-term and around 6 percentage points lower in a 'no Brexit' scenario.
Minister Donohoe told the Joint Oireachtas Committee on Finance that the reduction in the pace of growth would have negative spill-overs to the public finances and to the labour market.
In his opening statement to the Committee, he said the unemployment rate would increase by an estimated 2 percentage points, relative to Budget 2019 projections.
The most adverse impacts are likely to be felt in the agri-food and indigenous manufacturing sectors and the impact in certain exposed sectors and regions will be worse than the average.
"It is important to recognise that such estimates may not capture the full impact, and the figures may be conservative", the Minister said.
Paschal Donohoe also used his opening statement to address the recent launch of a paper by the European Commission on moving 'Towards more efficient and democratic decision making in EU tax policy'.
Mr Donohoe noted that since 2015, unanimity had not prevented the agreement of "an unprecedented 21 different tax initiatives by all Member States".
He said the Commission Roadmap identified the 'passerelle clause' as being the most feasible option for moving away from the unanimity voting procedure.
The passerelle clause would allow the European Council to unanimously decide moving an entire policy area or part of a policy area from unanimity voting to Qualified Majority Voting (QMF).
The support of the European Parliament as well as national parliaments, including Dáil Éireann, would also be required.
"This is a highly sensitive suggestion for many Member States, including Ireland, as any move to change the voting method, used for tax files, would reduce Member States' sovereignty," the Minister said.
"Given the large volume of important agreements reached at EU level on tax issues, I do not see the need for, or merits of, any proposals to move away from the requirement for unanimity", he said.
Mr Donohoe described membership of the Single Market and Customs Union as a core element of Ireland's economic strategy - including in attracting business, both over the decades and more recently.
"That will not change", he said adding that Ireland would remain an "active and enthusiastic" member of the EU.
"It is our view that all Member states, working together for the benefit of the whole Union, is the way to achieve the best results and real tangible progress," he stated.