The Minister for Communications, Pat Rabbitte, has queried the necessity of the communications regulator to pursue legal action against An Post.
The legal action relates to the imposition of a €11.9m fine on An Post for failing to meet next day delivery targets.
In 2004, ComReg issued a direction to An Post to deliver 95% of letters posted by the following day.
However, in the first quarter of this year, An Post reached just 85%.
ComReg is now pursuing a High Court action.
Speaking on the RTÉ's News at One, Mr Rabbitte said that the late delivery of letters was not an issue about which TDs received many complaints.
He said that An Post has made what he called "remarkable improvements" in the face of economic challenges.
Minister Rabbitte said, "I made very plain that ComReg is the independent regulator."
He continued, "The question is, can it discharge its functions short of resort to the High Court and at a time of such financial crisis for the country and for the company, is it necessary to go this route."