The Financial Services Ombudsman has warned that hundreds of borrowers who believe they were affected by the tracker mortgage scandal may find their complaints judged out of date.
Already, 103 complaints relating to tracker mortgages are being assessed as banks believe that borrowers left it too late to lodge their claim. However, Ger Deering said up to 500 complaints are likely to require further assessment.
Mr Deering has expressed concern that banks are using the time limit clause to potentially exclude some of those affected.
He said he is currently dealing with 1,141 complaints related to tracker mortgages. Of these, 103 are being assessed with regard to whether or not they fall outside the statutory time limit, but he expects this number to increase.
"My best estimate at this stage is that a time limit assessment will most likely be required on over 400 of those complaints," he said.
Some banks are "rigorously challenging the jurisdiction of this office to deal with complaints where there is a question in relation to whether the complaint was made outside the time limits," he told RTÉ radio.
This is despite an understanding in a framework set up between the Central Bank and the lending institutions that they would not raise the statute of limitation defence.
Fianna Fáil's spokesperson on finance, Michael McGrath TD said challenging the validity of claims on the basis of a rule that was introduced to protect customers "completely undermines their argument that the culture within the banking system has changed".
"This strategy of seeking to prevent cases being examined will inevitably cause further damage to the banking system at a time when it badly needs to rebuild public trust and confidence. The best way of dealing with this now is for all lenders to make a public statement that they will not seek to block the Ombudsman from assessing any complaints relating to the tracker mortgage scandal."
In its final review of the tracker mortgage scandal the Central Bank found that 40,000 customers had been affected and that banks had paid out almost €700 million in compensation. It also found 99 people had lost their homes as a result of the practice.