The Central Bank is understood to be reviewing a restriction which prevents banks from contacting a mortgage customer in arrears more than three times a month.
It is understood the banks have lobbied to have the measure - which was included in a revised Code of Conduct on Mortgage Arrears - changed. But mortgage brokers say the new restrictions were introduced only at the beginning of the year.
PTSB holds out prospect of lower rates
Meanwhile, Permanent TSB has said talks about the future of the bank could result a reduction in standard variable mortgage rates.
The development comes as Fianna Fail has raised the issue of 80,000 of the bank's customers who have seen home loan costs rise while the European Central Bank has cut rates.
A spokesman for Permanent TSB said it was intensive talks with the Department of Finance about the future of the bank. Depending on the outcome of the talks, it said, there could be a reduction in rates.
Fianna Fáil has accused the Government of abandoning 80,000 mortgage holders it says are being "crucified" by high interest rates.
The party says standard variable mortgage holders in Permanent TSB are being charged interest at a rate of 5.19%, while the Government forced AIB to reduce its variable rate to 3%.
Finance spokesperson Michael McGrath said it was unacceptable that one State-owned bank should be forced to reduce its rates, while another was ignored.
He said he could not understand the difference in attitude towards the two banks, but suspected that the Government prioritised AIB because of its market share and its higher visibility.
Deputy McGrath urged PTSB mortgage holders to contact Government TDs to urge them to support a Fianna Fáil private members motion, which is to be voted on tomorrow night, calling on the Government to use "all means possible" to bring rates down.
The motion also calls for greater efforts to increase lending to small and medium enterprises, and to help distressed mortgage holders.
Deputy McGrath said the Taoiseach and the Tánaiste admitted last week that they had not done enough on mortgages - and he said he agreed with them.
