Outcry as Civil Service spends £30m employing temporary staff after axing 3,000 posts
Nearly £30m was spent in two years by drafting in temporary staff to plug gaps in the civil service.
The trade union NIPSA branded the issue of agency workers "a blight on our public services".
It said a lack of proper workforce planning meant that thousands of public sector staff were denied job security and could "be let go at the drop of a hat".
Figures obtained by this newspaper in a Freedom of Information request show that from April 2017 until March 2018, £18.1m was spent employing 1,275 agency staff.
In the previous 12 months, £11.8m was spent on 812 temporary workers.
A total of 3,000 permanent staff had left the Northern Ireland Civil Service (NICS) in its controversial voluntary exit scheme between September 2015 and May 2016.
More than £90m was spent on redundancy packages.
However, the Department of Finance defended the employment of so many temporary workers saying the expenditure represented 1.3% of the total NICS salary bill.
It said: "The use of agency staff is a legitimate and necessary way to manage some aspects of temporary work and meet particular business needs.
"This is normal practice in any modern large organisation providing a range of services to the public."
Asked if civil servants who had taken voluntary redundancy had subsequently come back as agency workers, the Department of Finance said: "Agency staff are not employees of the NICS.
"It is for the relevant agency to provide the best people for the jobs."
TUV leader Jim Allister said clear answers were needed.
He said: "To me the most shocking aspect of this matter is not just that the SF/DUP executive spent £90m on financial handshakes under the voluntary exit scheme, but then (the civil service) will not say how many of those who left came back as agency workers at further huge cost."
Mr Allister added: "Where was the financial sense in compensating people to leave and then taking them back as agency workers? The extent and cost of agency workers since suggests to me that much of the voluntary exit scheme was ill-conceived and an expensive exercise."
NIPSA general secretary Alison Millar said: "The issue of agency workers is a blight on our public services. NIPSA has been raising this issue with the NICS and other public sector employers for the last few years.
"There is a lack of proper workforce planning which means that hundreds if not thousands of staff working in the public sector have no job security and can be let go at the drop of a hat. The reality is a number of them have been there for years."
Ms Millar said that it was in the union's view a "cynical ploy" to keep agency workers "in their place".
She continued: "They are not able to access proper public sector pensions nor access mortgages or make long term financial commitments - they are stuck in a time warp.
"This is not the fault of the many hard working dedicated agency staff who want a proper permanent job.
"NIPSA continues to raise this issue for proper workforce planning for the NICS and other public sector employers."
Ulster Unionist MLA Steve Aiken said his party had expressed concerns at the time about how the voluntary exit scheme was being rolled out.
"Not only was it giving large sums of public money to some people who would have already been shortly leaving the Northern Ireland Civil Service anyway, but its chaotic rollout saw thousands of others leave in a totally unco-ordinated manner," he said.
"Essential positions were becoming vacant and departments and bodies simply had no choice but to fill them again, and often the only source of staff were agencies.
"Lessons must be learnt so that those same mistakes are never made again."