The Minister for Finance has said a sudden withdrawal by Ulster Bank from the Irish market would be "very serious" for the economy, employment and credit.
Addressing the Oireachtas Budgetary Oversight Committee, Paschal Donohoe said he is taking the concerns over the bank's future here very seriously.
"Ulster Bank is a very important part of the Irish banking sector and their sudden withdrawal and the consequences for our economy, for employment and for credit are very serious," he said.
"I am well aware of them and I have made those points directly to NatWest."
The minister said that the withdrawal of the bank from the Irish banking sector is something which there has not been a public statement about.
The statements that have been made by its parent, NatWest, are that it continues to be engaged in a review of its presence here in Ireland and its future, Mr Donohoe said.
"I have engaged directly with Natwest myself, I have spoken to the chairperson of NatWest and I have reiterated to him what I have said in our Dáil, which is the concern that I have regarding the commentary and speculation, what it would mean for our economy and what it would clearly mean for those who depend on Ulster Bank for either employment or for credit or for investment," he said.
Mr Donohoe also said he had raised the issue in an engagement with the British Government, during a phone call with the Chancellor of Exchequer.
But he also added that it is not an issue in which he plays a formal role at all, as it is a commercial decision that is being made by a larger parent company in which the states does not have a share and which is making broader decisions regarding its own future.
He added that he has given a large amount of consideration to the effects of the possible withdrawal of Ulster Bank from the Irish economy, were that to happen, including for current account holders, for those who have mortgages and for those who are looking to secure credit in the future.
Sinn Féin’s Finance Spokesman, Pearse Doherty, said the worst option would be if the Ulster Bank loan book was to be sold to a so-called "vulture fund", while the best option would be if it were to stay here.
Market analysts think it is likely that NatWest will provide an update on its review when it reports its annual results next week.