The Government is being called on to account for where the money from the additional pension levy is being spent.
Fianna Fáil say they have raised the issue with Finance Minister Michael Noonan in the Dáil, but that his reply was not satisfactory.
The extra 0.15% charge is estimated to bring in €270m over two years. However, Fianna Fáil put that figure at €300m after a strong performance of equity markets during that time.
Their spokesperson for finance Michael McGrath said: "That can be used to help pension scheme members where the pension scheme has got into difficulty...It should not be absorbed by the central Exchequer and spent on Government pet projects or frittered away for one reason or another.
"It should be spent for the purpose for which it was raised and that's something we will be following up with the Minister when the Dáil resumes."