Minister for Jobs, Enterprise and Innovation Richard Bruton has defended his stance that the abolition of the Seanad would yield annual savings of €20m.
In correspondence with the Referendum Commission last week, a senior Oireachtas official said it is not possible to give an estimate of how much the move would save.
The letter also states that a strong caveat has to be attached to the €20m figure, as this relates to costs that may not translate fully into savings in the event of the Seanad being abolished.
Speaking on RTÉ's Morning Ireland, Mr Bruton said it was up to Government to ensure the delivery of the savings.
He said some would be immediate savings, such as the salaries of Senators and their staff, and office and administration related costs such as phones, postage, printing and computer costs.
He said other savings would be made through redeployment of resources, which will be achieved through the Haddington Road Agreement for the public sector.
Speaking on the same programme, the chair of the Referendum Commission said that her office could not provide any clarity on the likely savings that might arise.
High Court judge Elizabeth Dunne said the Commission could not engage in any speculation on calculating the likely saving to be made from abolishing the Seanad.