Attempts are being made to have Denis O'Brien appear before the Banking Inquiry.
Fianna Fáil TD Michael McGrath has confirmed he wants to expand the terms of reference for the inquiry - with Mr O'Brien then being called in to give evidence.
It is thought that the businessman would be asked to give evidence from the perspective of a corporate borrower, given that the inquiry is already due to hear from large developers.
However, the proposal has not yet been agreed and committee sources have said they are reluctant to overlap with the work of the Commission of Investigation - while also expressing concerns about expanding the inquiry's workload.
A decision on the proposal is due next week and Deputy McGrath has declined to comment further.