The Government says merging several agencies into ministries will improve their efficiency and effectiveness but will require job losses.

Labour's Grant Robertson said the changes were not backed by research and would have a large 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."

About 55 positions will go as a result of the changes that were already widely reported after being leaked to media.

State Services Minister Tony Ryall said the Government expected savings of $20 million over the next three years by merging:

* The New Zealand Food Safety Authority into the Ministry of Agriculture and Forestry.

The Cabinet paper Mr Ryall also released today said about $1 million a year would be saved with about 20 jobs cut.

* Archives New Zealand and the National Library into the Department of Internal Affairs.

The paper said it did not think independent bodies were needed to retain independence and said Crown Law advice backed that up. Risks of losing specialist staff could be reduced through "good change management" and communication. Savings of $3m-$9m could be made with a set up cost of about $2.5m in the first year. Jobs were to reduce by 15. The National Library chief executive had wanted an amalgamation with Archives and did not agree with the move to put them into the ministry, the paper said.

* The Foundation for Research Science and Technology into the Ministry of Research, Science and Technology.

The move would create savings of up to $2m a year and up to 20 jobs would go.

Treasury said there was a risk that Crown Research Institutes would be favoured but the paper said measures would be taken, such as an advisory panel to be set up, would mitigate that.

Mr Ryall said the Government needed to future-proof agencies during a time of increased 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."

Changes were also being made to lift the performance of state sector agencies and ensure agencies were working together to strengthen cross sector arrangements, he said.

Labour Party state services spokesman Grant Robertson said he was concerned by the announcement.

"I think particularly when you look at the merger of the Food Safety Authority back into MAF what could be more important for New Zealand's exports than a robust food safety regime?" he told NZPA.

"In 2007 the Government had an independent review that recommended the separating out of the Food Safety Authority."

Now it had been rolled back in without research or consultation.

"I think this actually has the potential to damage our economy, our image overseas and the quality of services New Zealanders get... I just don't think the benefits outweigh the costs."

On Archives and the National Library, Mr Robertson said it was telling the chief executive was not supportive of merging into a department.

The institutions were critical parts of New Zealand's democracy and sharing of information and the Labour government separated them based on an independent report, Mr Robertson said adding they were already very efficient.

"It just seems the Government wants to reduce the number of agencies here without actually thinking about the quality of the services they deliver... it's a very small amount of money for a huge amount of upheaval."

The Cabinet paper also says steps are under way for more online delivery of services and more bundled social services rather than separate delivery through agencies in and outside of government.

Social Development was working with IRD to deliver services online through a "service link", Economic Development was leading an all-of-government approach to procurement.