Finance Minister Brian Lenihan says there should be no need for confusion about the future of mortgage interest relief.
More than 50,000 people currently receiving the relief will have it suspended from tomorrow pending a review of their cases by the Revenue Commissioners.
The move follows an announcement in the recent emergency Budget that the relief will only apply for the first seven years of a mortgage.
First-time buyers who bought their home within the past seven years will not be affected.
The move has caused widespread confusion, but Mr Lenihan insisted this morning that the change was simple.