A lack of supply which is forcing people seeking to rent accommodation to bid against each is driving up prices, and not landlords, the chair of the Residential Tenancies Board has said.
Tom Dunne said the "notion" that landlords charge what they want is "not quite the whole story", and said tenants in a market where there is a lack of supply bid against each other to secure available accommodation.
Speaking on RTÉ's Today with Claire Byrne, he said: "So it is demand that is increasing rents, people who supply accommodation are kind of price takers in the market."
Mr Dunne said people will often pay more to achieve security of tenure and this is what is currently happening with a shortage of accommodation to rent.
"In any market you pay more for reliability. If you look at the research carried out the impact of this on people who are most vulnerable is very problematic. There is no doubt about that."
He said the problem will not be resolved without an increase in supply, and warned against increasing the Housing Assistance Payment, because those who receive the subsidy may be able to outbid those on low incomes but who do not receive HAP.
Mr Dunne acknowledged that those currently on "vulnerable incomes" who are in the private rental market, are "in very precarious circumstances."
But he rejected the proposal that rules around evictions should change as he said he believes this will create more problems.
Mr Dunne said that if the rules change it may encourage landlords who rent out their accommodation temporarily to no longer be encouraged to do so because it would mean they cannot regain possession.
He said attempts to move into the market and adjust the rules will result in "other problems arising elsewhere" and said the Housing Commission has to come up with a vision to look at the balance between renting, owner occupation and social and affordable housing.
