Older public servants have borne the brunt of recent government job cuts.
In the past two years, 412 government workers aged over 55 have been laid off, 42 per cent of the 970 redundancies in 10 agencies, figures released under the Official Information Act show.
Opponents say the loss is undermining the country's democratic process.
Of eight major government ministries and departments which fully answered questions from The Dominion Post, all had laid off more older workers than young ones.
The highest levels of redundancies at the Department of Internal Affairs and the Ministry of Education were for workers aged over 40, weighted for the number of employees currently employed in that age band.
The skew was even more pronounced at the Department of Conservation and ministries of Business, Innovation and Employment, Education, Health, Justice, Primary Industries and Social Development.
At these agencies, workers over 55 had most commonly received severance in the past two years.
The Ministry of Defence withheld information for privacy reasons, while the Department of Corrections declined to provide answers to all questions.
Most cuts came at the Department of Conservation, where 249 roles were slashed. About one in five department employees aged 55 and over had lost their jobs since December 2011.
The Public Service Association's Brenda Pilott believed the Government initiative to condense levels of management was one factor behind the age skew.
"In that case, it is inevitable you're going to be losing people who are in the older age group, as they've moved up into those middle and senior roles."
Another reason might be that people further along in their careers might be more willing to take voluntary redundancy when offered, she said.
"[Senior employees] do find it increasingly difficult to get jobs that actually utilise the skills and experience they've got - it is a very difficult time out there."
Deputy State Services Commissioner Sandi Beatie agreed older workers were more open to taking voluntary redundancy.
More than 1000 new staff aged over 55 also started working for nine out of the 10 government departments in the two-year period, she said.
Labour state services spokesperson Maryan Street said the figures showed the public sector had lost many of its most experienced employees.
"The Government is, I think, deliberately stripping out the institutional knowledge and experience of the public service.
"This leaves a workforce that is not going to challenge anything ministers do and that is one of the things the public service is there for . . . It's not good for our democratic apparatus."
About 2.5 per cent of all public servants at the nine government agencies were made redundant over the past two years.
- The Dominion Post