The managing director of Superquinn, Senator Feargal Quinn, is to be questioned tomorrow at a meeting of an Oireachtas Joint Committee about recent disclosures that he asked for "support payments" from suppliers.
The Committee on Enterprise and Small Business is meeting in special session to discuss the allegations which were made last week by a number of suppliers.
However, some of the members of the committee - including Ms Nora Owen TD and Mr Michael Darcy TD - have objected to Senator Quinn's appearance.
Ms Owen said inviting Senator Quinn to appear would "preempt" the current investigation being carried out by the Director of Consumer Affairs, Ms Carmel Foley.
She has submitted a formal objection to the committee's chairman, Mr Ivor Callelly TD.