Liam Lawlor has told the Planning and Payments Tribunal it must find another way to help him meet its demands.
The former Fianna Fail TD says there is no way he can meet massive legal costs to solicitors in London and Dublin for furnishing documents to the inquiry.
Earlier, the Tribunal accused the former Deputy of failing to co-operate adequately with its investigations, as he had failed to provide details of financial and property transactions which it had requested.