Dun Laoghaire Rathdown County Councillors have rejected a call to impose the full Property Tax on households in 2018.
For the the last three years all four local authorities have voted in favour of cutting the rate by the maximum of 15%.
However in recent weeks the councils' CEOs have urged them not to do the same next year, because they need the cash for services.
DLR's chief exec warned if the Property Tax was reduced again, it would mean charges like commercial rates or parking fees would have to be raised to compensate.
Last night the south Dublin reps rejected that call and also voted down a compromise of reducing the the cost by 5%.
Across the city in Fingal local reps voted in favour of reducing the Property Tax next year by 10%.
They're the first group of Dublin councillors not to give homeowners the full 15% discount.
It means there'll be an extra 2 million euro in the council's budget.
Dublin City Counillors will meet next week to decide on the rate cut.