The Public Service Association is calling on the Government to "come clean" about its plans for restructuring the public service.
State Services Minister Tony Ryall announced yesterday the New Zealand Food Safety Authority was being merged into the Ministry of Agriculture and Forestry, and Archives New Zealand and the National Library into the Department of Internal Affairs.
The Foundation for Research, Science and Technology will be merged with the Ministry of Research, Science and Technology.
About 55 jobs will be lost as a result of the mergers, and Public Service Association (PSA) national secretary Brenda Pilott said they signalled the first stage of a rolling restructure.
"The Government needs to end the secrecy and tell the public and public service staff what its plan is for the public sector," she said.
"Our experience is that mergers of government departments are expensive, disruptive and complex with no guarantee that the money spent and the upheaval caused will improve service delivery."
Ms Pilott said PSA members at the National Library and Archives were briefed yesterday afternoon.
"These members are shocked and angry," she said.
"The Government's decision does not make a strong case for amalgamating the National Library and Archives into the Department of Internal Affairs. There is no real reason given to take this step."
Mr Ryall said the Government expected savings of $20 million over the next three years.
He said the Government needed to future-proof agencies during a time of increasing financial restraint and rising public expectations of service delivery.
"Some agencies are going to need to work differently within their existing baselines to meet those expectations," he said.
Labour's state services spokesman, Grant Robertson, said the changes were not backed by research and would have a big impact for little savings.
"Simply having an agenda of cutbacks and reducing the number of agencies isn't necessarily going to deliver quality services for New Zealanders," he said.