ULSTER Bank has already sent out summonses to residential homeowners seeking to repossess their homes – the first move of its kind by a major lender.
It comes just days after the bank was included in a Government and Central Bank plan to tackle mortgage arrears.
Ulster Bank repossessed around 200 properties last year, but says that figure is likely to jump five-fold to 1,000 properties this year.
David Hall of the Irish Mortgage Holders Organisation accused the bank of taking an excessively aggressive approach to borrowers in arrears.
He said the bank was "gazumping" attempts by the Government to tackle the mortgage arrears issue by setting targets for lenders to offer solutions to distressed borrowers.
And banks were acting now to deal with those in the biggest financial difficulty to ensure they were not forced to write off debt under the new personal insolvency process coming in by the summer.
The move by Ulster Bank to send summonses threatening repossession is despite the fact that the Government has yet to restore the rights of banks to take back properties.
The Government has promised legislation by the end of the month in this regard, but the High Court heard this week the new law has yet to be drafted.
Ulster Bank boss Jim Brown said the bank was planning to repossess at least 1,000 homes a year once this legal loophole was closed.
"Our intention is to keep as many people in their homes as possible," Mr Brown said. He added that most customers in arrears could not pay their debts, but some would not pay.
"Foreclosure will be part of the process. The number will rise significantly as soon as we have the tools and legislation to do it."
A spokeswoman for Ulster Bank said it continued to communicate with its customers who were in mortgage arrears.
"We remain committed to working with any of our customers who are experiencing difficulty and who engage with us on a genuine basis to find a solution on a case-by-case basis."
The bank called on customers to contact it if they were experiencing financial difficulty.