Up to 20 new towns in Cork, Galway and in counties along the Dublin commuter belt will see rent caps within weeks.
Landlords can only increase rent by 4pc a year for the next three years in designated zones.
Housing Minister Simon Coveney is expected to reveal the new rent pressure zones before the end of the month following a review of prices in several counties.
However, Fianna Fáil is set to call for almost 40 towns to be designated as pressure zones due to rising rents.
Mr Coveney tasked the Housing Agency with identifying towns where rent caps should be introduced across 15 specific electoral areas. The report is almost finalised and it is understood the vast majority of areas reviewed met the criteria needed.
"I expect quite a number of towns will be included and quite a number of towns would like to get in but won't," Mr Coveney said.
Housing is increasingly becoming a flashpoint between the two largest parties. The Government yesterday escaped an embarrassing defeat in the Dáil after the Ceann Comhairle used his casting vote. TDs were voting on a bill aimed at tackling evictions when the numbers were tied 51-51.