Joan Burton has called for the chief executive of Rehab to disclose her salary, in the midst of a row over the money generated by the charity from scratchcard sales.
Minister Burton's cabinet colleague Alan Shatter sparked a row with the organisation last night when he revealed that Rehab made a profit of less than €10,000 on scratchcard sales of almost €4m in 2010.
He also questioned a "costly" legal action the charity has taken against the state, in which he said Rehab is suing the State for up to €1.5bn in a separate litigation under competition law, in connection with the operation of the National Lottery.
His comments drew a furious response from Rehab, which is demanding an apology.
"It is with considerable surprise that the Rehab Group learned that Minister Alan Shatter made comments in the Dáil on matters that are clearly pending before the courts and in which the State is the defendant," Rehab said in a statement.
"For a Minister who was or is a solicitor and thus an officer of the court to comment in this manner is simply outrageous.
"We expect the Minister to withdraw his remarks and apologise."
The organisation said it was "very disappointed in the Minister's conduct".
The charity sector is coming under increasing pressure over transparency in the wake of the Central Remedial Clinic controversy.
Rehab's chief executive, Angela Kerins, has so far refused to reveal how much she earns.
Minister for Social Protection Joan Burton said openness in the charity sector was very important.
"I would be on the record that people (and not only Angela Kerins) in the charity sector should disclose their salaries, and the salaries should not be excessive," she said.
Angela Kerins recently called for transparency in the charities sector, but refused to reveal her salary when asked a number of times. Her salary is believed to be around €240,000.