Kieran Mulvey said if progress is not delivered then decisions will be made for them by the IMF, EU and ECB.
Speaking on Newstalk, Mr Mulvey, who brokered the agreement, said those decisions could cause significant industrial relations and social trouble.
He estimated that the parties to the agreement, including unions, public service management and industrial relations bodies had until September to address the issue.
The comprehensive expenditure review commissioned by Public Expenditure and Reform Minister Brendan Howlin is due by that point.
Mr Mulvey voiced concern that people seemed to be taking the scenic route to change.
He said Ireland was going to face major decisions by international organisations that were paying the wages of many people in the country.
If we did not make progress ourselves, he said, those organisations were going to come up with solutions for us.
Mr Mulvey urged the parties to engage as a matter of urgency.
He acknowledged that the Croke Park Agreement had delivered significant savings, with over 16,000 public servants leaving the system over the last two years without being replaced.
