The Oireachtas Banking Inquiry's been told that Anglo Irish Bank should have been liquidated when the bank guarantee was introduced.
Professor Patrick Honohan, the governor of the central bank, also says Brian Lenihan wanted to nationalise Anglo Irish Bank on the night the guarantee was introduced - but he was overruled.
The governor says he understands the decision to introduce the guarantee, because politicians weren't given a full picture of how bad the situation truly was.
He says the net cost of the guarantee is now around €40 billion.
He told TDs and Senators that Anglo Irish Bank could have been excluded from the guarantee, and would have been able to trade until the end of the week before being liquidated.
And he's admitted that financial regulation totally failed in Ireland, because regulators paid too much attention to the 'medium' projections and not enough attention to the worst case scenarios that might have unfolded.
Our political correspondent Gavan Reilly filed this report for Today FM's National Lunchtime News:
