The Irish Mortgage Holders Organisation has said the timing of changes to the Local Property Tax is unfair and odd.
The changes will mean an average increase of around €90, but not for everyone.
The Department of Finance says this estimate is "notwithstanding significant increases in property values since 2013."
The rate of the tax is to be cut and the bands will be widened - while property valuations are to be reviewed every four years.
Homes built since 2013, which have been exempt to date, will be charged from November. The first bills will arrive early in 2022.
The effect of these changes, combined with bringing properties built since 2013 into the charge, is projected to deliver €560m.
David Hall, from the Irish Mortgage Holders Organisation, told Pat Kenny it is a bizarre decision.
"The key part here is that there is an imbalance on a tax that needs to be balanced - that's accepted.
"But I think the timing of this where people are coming out of a public health pandemic, are under immense pressure, a significant number of people are under pressure to return to work... for their jobs and businesses to remain the same.
"To be faced with such an immediate change in the taxation system for them is very odd at this time.
"It's an €80m benefit that's coming into the State - based on yesterday's even announcement of €4bn in the stimulus that's required.
"Many people have been under immense pressure over the last 18 months - not just those who are facing unemployment, facing a dramatic reduction in their set of circumstances - to be now faced coming out of a pandemic with the first signal of an increase in taxation is peculiar timing to say the least."
Post-pandemic debt
He said many people will also have debts accrued after the pandemic.
"In the UK they've looked at things much differently, in a more mature way, recognising that many people have debts after [the] pandemic.
"Yes there is government supports given, but other people have incurred debts and have needed breathing space to gather theirselves after the pandemic.
"Indeed they introduced breathing space legislation to allow for all such debts not to be collected for the next 60 to 90 days.
"Here, we seem to be looking at a concept of walloping people straight away after this."
And he added that there is an assumption that somebody in a house of particular value has an income to support themselves.
"That's an unfair assumption that's made on all occasions, and I think that's where the unfairness comes at this time - this time is a critical time.
"Many people don't even know by next year whether they'll have a job or not."
The new system
The new approach keeps the number of property tax bands at 20 but expands them.
Band 1 is expanded from €1 to €200,000 and Band 2 contains values in the range €200,000 to €262,500.
The charge is fixed at the current charge for bands 1 and 2 (€90 and €225 respectively).
The other bands are widened by 75% to create bands of €87,500 (increased from the current range of €50,000).
For properties in Bands 3 to 19, a mid-point rate of 0.1029% will be charged.
Properties in Bands 12 to 19 (between €1.05m and €1.75m) are charged a mid-point rate of 0.1029% on the first €1.05m, and 0.25% on balance over €1.05m.
Properties in Band 20 are charged on individual property values as before (0.1029% on first €1.05m and 0.25% between €1.05m and €1.75m, and 0.3% on balance).
The Department of Finance has outlined several examples under the new system.
House in Dublin
Valued at €260,000 in 2013, Current estimated value €445,000
Increase in value approx. 71%
Remains in Band 5 Liability €495
House in Cork
Valued at €235,000 in 2013, Current estimated value €300,000
Increase in value approx. 28%
Liability – drops from Band 4 to Band 3 Liability decreases from €405 to €315
House in Midlands
Valued at €80,000 in 2013, Current estimated value €186,500
Increase in value approx. 133%
Liability – €90 Remains in Band 1
House in Galway City
Valued at €123,000 in 2013, Current estimated value €240,000
Increase in value approx. 95%
Liability – €225 Remains in Band 2
House in Dublin
Valued at €250,000 in 2013, Current estimated value €475,000
Increase in value approx. 90%
Liability – Increase from €405 to €495 Band 4 to Band 5
House in Border county
Valued at €65,000 in 2013, Current estimated value €140,000
Increase in value approx. 115%
Liability – €90 Remains in Band 1
Higher Value property Dublin
Valued at €1.05m in 2013, Current estimated value €1.6m
Increase in value approx. 45%
Liability – increase from €2,063 to €2,502 (Move from Band 20 to Band 18)