Fianna Fáil has said it is unacceptable for the Department of Justice's top official to refuse to answer questions about the resignation of former Garda Commissioner Martin Callinan.
The department's secretary general Brian Purcell will attend the Justice Committee next week, where TDs want to ask him about the Guerin Report and the controversies surrounding the Gardaí in recent months.
However Mr Purcell has said he won't answer questions on Mr Callinan's resignation, which came hours after Mr Purcell was sent to meet him by the Taoiseach.
Fianna Fáil's Justice Spokesperson Niall Collins says that's not acceptable.
"Absolutely not… I don't think it's acceptable under any circumstances that a senior civil servant would seek to dictate to a committee of the Oireachtas what he or she would make themselves available for scrutiny and questioning upon," Deputy Collins said.
"We are elected by the people and we are there to serve the public interest."
His comments were echoed by junior minister Brian Hayes, who said no senior official has the right to set the terms of what can and can't be said before a committee.
Fine Gael's MEP candidate also agreed with comments made by the Transport Minister Leo Varadkar that the Department of Justice is not for for purpose.