Central Bank officials have been summoned to appear before the Oireachtas Committee on Finance today, for questioning over the Ulster Bank scandal.
Some 150,000 customers of the bank are now into their third week of disruption, with the bank saying they cannot confidently predict when normal services will resume.
It comes ahead of an appearance at the committee tomorrow of Ulster Bank officials themselves.
Committee Chair, Dublin South TD Alex White, said he will be asking the Central Bank, as the regulator, what kind of controls it has in place to safeguard against technical malfunctions at banks.
He also wants to know what kind of supervision officials exercise over banks like Ulster Bank.
"Questions require answers - that's the idea for us having these parties in before the Committee," the Labour party deputy said.
"I think it's vital for public confidence in the banking system generally - obviously here we are talking about Ulster Bank - confidence and trust is hugely important in banking, particularly nowadays.
"We will be expecting, and I'm sure the public will be expecting, for the bank and its representatives to answer up for their apparent failing."