Croatia on Monday proposed raising the retirement age to 67 from 2031, and trade unions said they would protest.
The current retirement age is 65 years for men and 62 for women, although women's retirement age is due to rise gradually over the next 12 years to 65.
Under the new proposal, which the labour and pensions ministry put forward for a public debate in the next three weeks, men and women would have to retire at 67 from 2031.
The ministry also proposed that pensions would be 4 percent lower for each year of an earlier retirement.
Labour Minister Marko Pavic said the goal was to make the pension system sustainable and pensions higher in the future.
The main trade unions said they were likely to organise protests in the coming weeks, saying the measures would hit older employees who are often under pressure to retire earlier for health reasons or because employers wanted to get rid of older staff.
Each year the budget needs to finance about 17 billion kuna ($2.69 billion) from taxes to cover a gap in the pay-as-you-go public pension scheme which costs about 39 billion kuna annually.