REHAB Group has indicated it will not discuss details of the salaries of senior executives when it appears before the Dail's spending watchdog today.
A lawyer representing the charity and commercial group contacted the Public Accounts Committee (PAC) indicating it believed such matters are outside the PAC's remit.
The move has incensed several members of the powerful committee which had been seeking to question Rehab's remuneration committee, as well as its chief executive Angela Kerins and its former chief executive, Fine Gael strategist Frank Flannery.
However, it now appears that only Mrs Kerins will appear, along with representatives of state-funded Rehab subsidiaries National Learning Network and Rehab Care.
A number of committee members had called for the full disclosure of salaries and pension entitlements of senior executives.
While some figures are known for senior staff members at the National Learning Network and Rehab Care, they have largely not been disclosed for elsewhere in the group.
That is because Rehab maintains these salaries are funded from private earnings and not from the €83m in state funding it received last year.
PAC chairman John McGuinness said it was important there be clarity on salary levels.
"The charity sector in Ireland has suffered greatly in recent months and it is essential that trust and confidence is restored through the transparent use and reporting of donated funds," he said.