A tax expert has said the proposed new property tax should perhaps be deferred until 2014.
The Government said the new tax will be introduced next year and will replace the €100 Household Charge.
Fergal O'Rourke of PricewaterhouseCoopers, who was a member of the Commission on Taxation in 2009, has said there are still many details to be worked out before the new tax is introduced.
Mr O'Rourke said: "I just have a concern that in the rush to introduce this in 2013, there is an awful lot of detail that we have not seen yet.
"Personally, I would say they are better off getting it right rather than gettting it in quick, and I suspect the continuation of the €100 charge may be tweaked up.
"It might be in the minds of the Department of Finance or the Department of the Environment for the next 12 months, with a view to having a very comprehensive system in 2014."