The Financial Services Ombudsman has said naming banks that are the subject of complaints to his office would create a "virtuous competition" in the institutions' behaviour towards customers.
Speaking to RTÉ's This Week, Bill Prasifka reiterated a call for his office to be granted powers to release details of complaints against individual banks.
He said making the complaints record of individual banks public would influence how they behave.
Mr Prasifka said the measure would be in the public interest, could be done at no cost to the exchequer, and should have been introduced a long time ago.
The Ombudsman was commenting on the conduct of banks in relation to complaints by tracker mortgage customers, in particular where borrowers had lost their tracker rates after opting to fix mortgages for a term.
He said there had been some improvement, and that some of the banks had now settled all or almost all of their tracker complaints according to guidelines and methodologies his office had set out.
But he said others were fighting each case.
A Fianna Fáil private members bill making provision for the Ombudsman to be allowed to name financial institutions in its reports went to committee stage in the Oireachtas last year, with the government expressing support for the overall principle of the bill.
However the measure has yet to be implemented.
Sinn Féin Finance spokesperson Pearse Doherty has said naming and shaming banks was one aspect of empowering consumers to be aware of what is happening in banks.
Speaking to RTÉ's This Week, he said legislation on the issue was "not before us yet".
Mr Doherty said legislation which related to protecting the consumer was always left on the long finger while other legislation was rushed through.