PUBLIC Expenditure Minister Brendan Howlin has insisted any cuts to public sector allowances will be made in the context of the Croke Park Agreement.
He said while no decision has been made over which workers are to see their perks stopped, they will not be confined to new appointments alone.
"It's been known for some time that all allowances are under review," said Mr Howlin.
"There is more than 800 of them and we've asked for each parent department to make a business case in relation to each, and they've done that.
"Some business cases are still coming in and we are evaluating all of that for the most part."
The minister announced yesterday that the estimated 800 allowances paid to public servants will not be protected as core pay under the Croke Park Agreement.
The state pays around €1.5bn a year to staff in relation to allowances which include money for overtime, expenses and premium payments.
But Mr Howlin argued that the allowances should not be covered in the 2010 agreement, in which the Government pledged to protect public servants' pay until 2014 in exchange for workers' commitment to be flexible and increase productivity.
He said some of the allowances were historic and pointed out that some expenses claims in particular would cause a few raised eyebrows.
"Any changes will apply to new appointments but there may be some existing allowances where there isn't a robust business case, so we've made no decisions on any of that," Mr Howlin went on.
"And obviously it will all be done in the context of Croke Park."
The move is likely to see the Government clash with trade unions again.
Three major unions have already gone up against the Fine Gael-Labour coalition, saying they support a No vote in the referendum on the European stability treaty on May 31.
These plans, in relation to civil servants' allowances, could drive a greater wedge between them.
Irish Congress of Trade Unions general secretary David Begg refused to be drawn into the issue.
"I think you should talk to my public sector colleagues about that," said Mr Begg when asked about the minister's comments.
"They competently deal with that. They know much more about the public sector than I do."