Housing charity Threshold received 73,526 calls last year, and a third were from tenants faced with losing their homes.
At the launch of its annual report for 2017 yesterday, chair Aideen Hayden said that of particular concern was the jump in the number of people contacting them in relation to tenancy terminations, with an 18pc increase compared with the previous year's figures.
Termination of tenancies during 2017 was the top issue raised, accounting for 32pc of all queries answered.
Most of the terminations were due to the sale of the property (38pc).
Seventeen per cent of notices were issued on the grounds of the landlord or family member moving into the property and 12pc were issued for reasons of refurbishment or renovation.
All of these grounds are permitted under the Residential Tenancies Act.
Threshold noted an increase in notices of terminations on the grounds of renovation work, or "renovictions"
It said it recognised that "this ground for termination was being used to terminate tenancies as well as circumvent rent pressure zone legislation".
In rent pressure zones (RPZs), rent increases are capped at 4pc a year over a three-year period.
Threshold noted in its report that "it became evident in 2017 that some landlords and agents were not adhering to the RPZ legislation, or were finding ways to circumvent it".
To counter this, the charity sought the publication of a "rent register".
Speaking yesterday, Ms Hayden said: "We are dealing with many people who come to our services who are facing unaffordable rent increases."
She pointed out that there had been significant changes over the past decade.
"We have seen a very severe fall in the number of people who own their own homes, and we have seen a very significant fall in the number of people who have been able to access social housing," she said.
"In its place, we see more and more vulnerable people living in the private rented sector.
"We see more and more Generation Rent - people who cannot afford to buy their own homes but who in reality are spending more money in rent than they would be in paying a mortgage."
Housing Minister Eoghan Murphy, who attended the launch of the annual report, said new legislation was on the way that would shore up protections for tenants.
"These include provisions to ensure the Residential Tenancies Board can inspect rental properties and make sure landlords are compliant with the rental caps in rent pressure zones," he said.
"I think it's very important that as we build new homes, at the same time we also bring in stronger protections for renters as well."
Mr Murphy said he would bring a new bill before the Cabinet next Tuesday.
"I absolutely support rent transparency," he said.
"I believe that rent transparency does mean having a rent register, and I see no reason why we can't do it like we have done with the property price register.
"I have told the Attorney General that this is what we want to incorporate in our legislation."