The Irish EU Commissioner, Mr Padraig Flynn, has said he will respond to Fianna Fail's letter "when the time is right".
The Taoiseach, Mr Ahern, said last week that the party had sent Mr Flynn a letter last October about the destination of a cash donation of £50,000 from the builder Mr Tom Gilmartin.
Responding last night to questions from RTE's Tommie Gorman, Mr Flynn said he had been surprised by the release of details of a personal letter from the party but accepted that there was "no legal certainty" surrounding matters to do with the Flood tribunal.
He insisted he would not be clarifying his position before giving evidence to the tribunal. "I will respond when the time is right," he said. To do so now would be inappropriate "because it would undermine the tribunal".