Tanaiste Eamon Gilmore has urged unions to stand back after they criticised radical pension reform plans and threatened court action.
The Foreign Affairs Minister said new measures to cut the public service retirement bill by 35pc, or €1.8bn, by 2050 are prudent.
The Into and Asti teachers' unions claimed the changes - which do not affect fast accrual rates for ministers, TDs, judges, nurses, gardai and firemen - are illegal.
But Mr Gilmore urged restraint and defended the reforms, announced yesterday by Minister for Public Expenditure and Reform Brendan Howlin to meet commitments given under the bailout loan deal.
"What is proposed in the Bill that Minister (Brendan) Howlin has published is a new approach to pensions for new entrants to the public service," he said.
"I think that is prudent. I think he has made it clear that for employees who are, particularly employees who are on low and flat incomes, it won't make any significant change to their pension entitlements. It is a measure that will be introduced over a period of time.
"I think Minister Howlin has made it clear that he's willing to talk to unions and look at what concerns they have about it. If they go the legal route that's their entitlement, that will have to be determined ultimately in the courts.
"But I think we need to stand back from this and look at what it is we're trying to achieve."
The public service pension reform will see retirees paid annual sums based on an average of their earnings during their career rather than the current case of their final salary.
Uniformed employees will not be affected as they are offered or subject to early retirement.
The Oireachtas is exempted from the reforms because of "special circumstances" such as fixed periods of employment.
But teachers' unions claim their members will be hardest hit, with increased payments outstripping their return on retirement.
Pat King, general secretary of the secondary school teachers' union Asti, said teachers would be oversubscribing and a legal challenge was being considered.
He added: "This is nonsensical and has to be open to legal challenge."
Sheila Nunan, general secretary of the primary school teachers' union Into, said it was probably unlawful.