The opposition justice spokesman has admitted it was a mistake to write a letter seeking leniency in the sentencing of a widowed father-of-four for drugs offences.
Fianna Fail's Niall Collins said he will not be resigning over the affair, which has seen him widely criticised for interfering in a judicial matter.
He said he will not do it again.
The Limerick TD said he wrote on compassionate grounds on behalf of Hugo Porter, 40, of St Patrick's Villas, Castleconnell, a widowed father who was convicted of possession of 17,500 euro worth of cannabis.
Mr Collins initially issued a statement over the controversy saying the case had exceptional circumstances and that he fully respected the judge's independence.
The letter was written last month after approaches from constituents to the Mr Collins on behalf of Porter.
Mr Collins said he decided to discuss the issue on RTE's Today with Sean O'Rourke programme today following continued criticism in political circles that he made an inappropriate approach to a judge.
He admitted it was a mistake to write a letter to Porter's lawyers which was then shown to the judge.
"Obviously it was a mistake. Of course it was a mistake, and I think the publicity that has surrounded this isn't going to support or serve the intent of my action," Mr Collins said.
The TD said he wrote purely on compassionate grounds on the back of the tragic circumstances where the mother of four young children has died.
"I was particularly struck by the circumstances of it. The way it is now, obviously, it hasn't been helpful at all to serving the intention or indeed the effect of my intention. It was a mistake and I won't do it again," he said.
"It shouldn't be done and I for one won't be doing it again."
At a court sentencing hearing a judge was shown the letter, which was not read out, and asked not to attach any weight to it.
Taoiseach Enda Kenny yesterday described the controversy as a very serious matter while Fianna Fail leader Micheal Martin defended his frontbench spokesman, saying he had acted because of exceptional circumstances.
Porter is to be sentenced in October.