There is a call for rental platform Airbnb to be fined for advertising "rogue properties".
It comes after the number of homes advertised on the site in the areas worst hit by the housing crisis rose by more than 1,000 last year.
The Irish Independent reports the number of entire homes advertised for short stays on Airbnb rose by more than 1,000 in Dublin, Cork, Galway, Limerick and Waterford - over the past year - to almost 6,900.
That is despite new regulations aimed at clamping down on short-term holiday lets being brought in last July.
Under the plans, homeowners are only allowed to rent out a room on a short-term basis if it is located in their primary residence.
Any secondary property cannot be used for short-term letting unless planning permission is approved.
It is up to each local planning board to decide whether or not to give that based on housing demands in the area.
People can let out single rooms in their private residence all year round - or the entire home for a maximum of 90 days a year.
The homeowner also has to register the short-term letting with their local council, and notify their local planning authority as to how many days a year the property is used as a short-term let.
But it is reported that just 370 applications to register have been received to date.
Sinn Féin's housing spokesperson Eoin Ó Broin has called on Minister Eoghan Murphy to fine Airbnb and other platforms for advertising rogue properties.
"New short-term letting regulations came into force in July 2019, and to date the vast majority of short-term letting landlords continue to flout the law.
"We now learn that there has been a significant increase in the number of short-term lets available at a time when long term rental supply continues to fall well below demand.
"It is time for the Minister for Housing Eoghan Murphy to introduce legislation to fine Airbnb and other platforms who advertise rogue properties, and a strong sanction on platforms would greatly assist local authority enforcement of the rules.
"There is no point in introducing regulations for the short-term letting sector without adequate enforcement."