Those new home buyers will lose more than €30,000 if they do not purchase a property before June when mortgage interest relief is to be stopped.
Currently mortgage interest relief is available to first-time buyers for up to seven years after they buy their property.
The changes to the relief — also known as Tax Relief at Source (TRS) — are outlined in the Programme of Government. The new measures include an increase in TRS for people who bought properties between 2004 and 2008.
Angela Keegan, managing director of property website MyHome.ie, said many first-time buyers are unaware of the full implications of the June deadline adding the new measures should be delayed until next year when the relief was due to be phased out on a gradual basis.
“Buying a house is the biggest and most important financial transaction people make,” she said.
“Introducing drastic changes like this at such short notice is particularly unfair to first-time buyers who have already been hit by a range of measures such as changes to stamp duty, more expensive mortgages and the unavailability of ECB tracker and fixed-rate mortgages.”
Ms Keegan said the news was bad for the property market as a whole.