A member of the Public Accounts Committee says it's not acceptable for Rehab to only answer questions they deem appropriate today.
Representatives from the group are due to face the Oireachtas spending watchdog over their lottery scheme.
Rehab solicitors have given advance notice that they're not willing to discuss CEO Angela Kerins' 240 thousand euro salary at the hearing - or any other issues outside the committee's remit.
Rehab's defended the salary paid to Angela Kerins, saying it's slightly below what she would receive for running a similar company in the private sector.
But two weeks ago the board of directors also refused to reveal the salaries of other senior managers - saying they would only do so in two years, when they're legally required to.
That subject is likely to be the major bone of contention this morning - as Rehab's legal team has told the Public Accounts Committee that the salary isn't up for discussion.
TDs have been told the group will only discuss the ways in which it spends its 82 million euro of state funding - and not any other financial issues.
However there will still be questions on the management of Rehab's lotteries - and particularly why its scratchcard lottery was able to sell tickets worth 4 million euro, but make a profit of less than 10000.
Sinn Fein Deputy Mary Lou McDonald says there are legitimate questions that need to be answered:
