Opposition parties have sought an assurance from the Government that other banks will not follow the lead of Permanent TSB if it puts up its variable mortgage interest rates.

Finance Minister Brian Lenihan said that no Minister for Finance since the foundation of the State had come into the Dáil and announced what mortgage interest rates would be.

He also pointed out that Permanent TSB had not applied to come under NAMA, nor had it sought any recapitalisation from the State.

Mr Lenihan added that Permanent TSB had paid for the benefit of the State guarantee and said the bank was in a difficult situation with historically low interest rates.

Both Fine Gael's Enda Kenny and Labour's Eamon Gilmore asked if this meant that banks that were under the NAMA umbrella would not increase mortgage rates, but Mr Lenihan declined to give such a guarantee.