The Chairman of the Oireachtas Finance Committee has said the Central Bank is not doing enough to "bring banks to heel" on the tracker mortgage scandal.
Speaking on RTÉ's Six One News, John McGuinness said it was not ensuring that the banks deal with their customers "in a way that gives them adequate compensation and not the pittance that has been given to some".
He said the exact number of people affected is not clear.
Earlier, the Taoiseach told the Dáil the Government had lost patience with banks for failing to deal with customers who were wrongly removed from their tracker mortgages.
Leo Varadkar said Minister for Finance Paschal Donohoe has called the banks to a meeting next week, where he will "admonish them for their conduct".
He said if the Government does not see results soon, it would provide the Central Bank with enhanced powers, or would increase taxes on the banks.
Mr Varadkar was responding to Labour leader Brendan Howlin, who said the banks were guilty of malpractice.
The Taoiseach also said the Central Bank was seeking a response from the banks in question, and if it was not satisfied with the response, it would publish the names of the lenders in question.
Mr McGuinness said figures from some financial experts support predictions that as many as 30,000 people could have been wrongly removed from their tracker mortgages and moved onto a higher rate.
The current figure is 13,000 people.
Mr McGuinness said he was happy that the banks would appear before the Finance Committee, but that "it is too late".
He said he hopes sanctions would be imposed on the banks involved, through the Central Bank, so that people can be paid before the end of this year.
Mr McGuinness said the banks involved have submitted families to the most awful financial circumstances.
He said they should to proactively deal with the "pre-2013 issue should show compassion and humanity to deal with the redress before Christmas".
Earlier, the Financial Services Ombudsman Ger Deering said it was disappointing that some banks were failing to co-operate fully with the Central Bank's investigation.
Speaking on RTÉ's Morning Ireland, Mr Deering said it shows that the culture in some banks had not really changed.
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The Central Bank released new figures yesterday that showed the number of mortgage accounts affected by the tracker scandal has risen by 3,100 to 13,000 since March.
In an update on its examination of the issue, the Central Bank said 23 mortgage holders have so far been identified who lost their homes as a result of being improperly moved from their low-rate tracker product to a higher rate loan.
A further 79 buy-to-let customers affected have also had properties repossessed. The Central Bank said it expects both of these figures to rise.
It also said that €120m has been paid to around 3,300 customers as a result of its examination.
Mr Deering said that his office had put complaints about tracker mortgages on hold, pending the outcome of the Central Bank's examination.
He said he believed the best way to deal with the significant number of complaints was for banks to co-operate with the Central Bank process.
However, if that did not work out for complainants, Mr Deering said they still had the right to bring a complaint to his office.
The Financial Services Ombudsman said it was difficult to say whether banks made a mistake in removing people from their tracker mortgages, or if it was a deliberate policy.
Mr Deering said that since 2009 his office had dealt with around 1,800 complaints. Decisions were made in around 700 cases, with roughly 25% of these customers being reinstated on their tracker mortgage.
In an investor note, Investec said the total number of cases that have received compensation and redress is 3,300, "indicating that that €163m figure is likely to increase significantly as time goes on, with a €500m total across the industry not unlikely.
"The report notes that the CBI is currently pursuing enforcement investigations in relation to tracker mortgage-related issues arising in PTSB and Ulster Bank Ireland, and that two further enforcement investigations into other lenders are in train, and it is anticipated that more enforcement investigations will follow."