A new report by Davy Stockbrokers says our banks may require another capital injection of up to €28bn.
It estimates that AIB, Bank of Ireland, Irish Life and Permanent and EBS could need an extra €24bn, to cope with higher-than-expected losses.
Results of the stress tests being carried out on the four banks are due next week.
Davy also believes that Anglo Irish Bank, which is not subject to the tests, will require a further €3.4bn.