It is assumed that the Deputy’s question envisages a movement away from the current system of marking of oil to which a reduced rate of tax applies to one in which certain users, who currently use marked oil tax paid at a reduced rate for specific uses, would instead be given refunds of part of the mineral oil tax paid by them in respect of fuel used for non-auto purposes. No additional revenue would accrue to the Exchequer as a result of such a system because any additional revenue raised would be subject to reclaim by eligible users. While it might be expected that the net mineral oil tax raised from the users concerned would be neutral, this might not be the case in practice as the risk of abuse and fraud might be greater than is the case with the existing system. A change of this kind would also require the establishment of an extensive repayments system, which would give rise to a significant additional administrative burdens and costs for oil traders, users and the Revenue Commissioners. It would also impose significant cash-flow costs on those currently using marked oil for certain purposes, including agriculture.