Permanent TSB Group chief executive Jeremy Masding has said it's "business as usual" at Newbridge Credit Union.
The Co Kildare lender is being taken over by Permanent TSB on foot of an order made at an emergency sitting of the High Court last night.
The decision ensures customer deposits are protected. It comes at a cost of €54m to the taxpayer.
Masding reassured deposit customers that their funds will be "used wisely", while telling borrowers "we're open for business".
"We were asked to bring certainty to a situation which had complete uncertainty," he said.
Tánaiste Eamon Gilmore said that the bailout of Newbridge Credit Union in Co Kildare is an isolated case.
"We would have preferred if it had been possible to have had an amalgamation of credit unions; this does not have other ramifications for other credit unions - this is something that has happened on a one-off basis," he said.
The members of Newbridge Credit Union claim their institution has been deliberately targeted by the Government.
An action group is now preparing legal action over the High Court approval last night for the takeover.
The group claims that the takeover is part of a government policy to move deposits from Credit Unions into State-supported banks.
Willie Crowley of the Newbridge Credit Union Action Group says the takeover forces people to deal with banks they deliberately avoided.
"What should somebody who chose to be a member of a credit union be now told that you can no longer do that, you must be a member of a bank," he said.
"The reason why we've had such a large number of member is precisely because of the trust that a community places in a credit union, and their distrust of a bank.
"This is why we have been so successful as an entity."