Public Expenditure Minister Brendan Howlin says he is confident the Government will secure the necessary €300m of public sector savings this year after Labour Relations Commission chief executive Kieran Mulvey (right) won agreement on a new deal.
Workers who fail to sign up to the new deal will not get to claw back their pay cuts in future years.
And they will also lose the protection against compulsory redundancies contained in the existing agreement.
The Government hopes the revised agreement will be accepted after striking different deals with individual unions. They have received guarantees that elements of pay now being cut will be returned in future years, and specific arrangements on the freezing of increments.
But any union outside the deal will not receive these benefits. The legislation being drawn up by the Government will freeze increments for three years.
However, unions that struck their own deals won concessions of pauses on the payment, dependent on the income band, which soften the blow.
Likewise, the pay cuts for those on more than €65,000 are due to be reversed in three years' time, but only for those who agree to the deal.
The threat of compulsory redundancy also hangs over those who do not sign up to the deal. Workers who sign up to the deal will be protected.
Although the possibility of compulsory redundancy will not be specifically outlined in the legislation, there will be disadvantages to rejecting the deal on offer.
A Coalition source said: "There will be items in the legislation which people won't find particularly attractive. It will be clear there will be advantages to being part of the agreement."
After frantic negotiations, agreement in principle was reached on a series of proposals with individual unions, several of whom will have to ballot their members again on acceptance of the deal.
Mr Howlin said there would be a different set of proposals for each sector, and in some cases for different unions in the same sector.
Appealing for public sector workers to back the agreement, he said the negotiations were "difficult and long" and warned that signing up to the deal was the only way to avail of its contents.
"I hope if we get an agreement that we will be able to give the same guarantees we've given to workers in the public sector to date that there will be no compulsory redundancy," he said, "but that's contingent on people signing up to the deal."
In the health sector, newly recruited hospital consultants earning more than €100,000 are to be spared another 8pc pay cut.
The move will maintain doctors' salaries at a reasonably competitive level amid evidence that some posts are becoming increasingly difficult to fill.
The major concession for teachers was around money for supervision and substitution, the allowance for which will be discontinued from September.
Payments worth €1,300 a year will be restored to teachers by 2017.
Mr Howlin acknowledged that the country's 300,000 public servants had already contributed to Ireland's economic recovery and reduced their standards of living in recent years, but vowed it would be the Government's "last ask".
"It is a building process to get to today," he said.
"I'm glad that the structure is there. I'm not taking anything for granted with regard to the ballot that's still out there.
"But I'm asking public servants to walk with us on this final leg of the path. I think it's really important."