Auckland councillors will vote tomorrow on whether to outsource operations, partially outsource them or retain the status quo of all the city's 42 swimming pools and leisure centres.
The Public Service Association, which represents council workers, is criticising what it says is a lack of public consultation on the proposal.
It says council pools and leisure centres are an essential part of community life and wellbeing and should remain in public hands.
Currently, 22 facilities are managed by the council but 20 are already managed by third-party providers.
A council report said that fully privatising the network would provide the greatest value for money, however, PSA president Benedict Ferguson told Checkpoint outsourcing to a private entity was not a good way to run a public asset.
"There's around 800 staff that work at the council-run facilities, of which about 200 to 220 are our members.
"We won't know the exact number that moves across until the decisions made, but our view is, any sort of any sort of outsourcing to a private entity is a pretty poor way to run a public asset, run a public service."
Auckland councillors to vote whether public pools operations should be private
Ferguson said the PSA was worried, as when a public service was outsourced to a for profit company, their main focus became making profit.
"For council staff who work in these centres, they're public servants, they're there for the public. They don't have that a for-profit mentality.
"They're really there to build communities, make sure our communities have the well-being and the services they need that are run by our pools and legislators."
Private companies, in the short term, were able to deliver a minimal amount of efficiencies, he said.
"We think it's much better to keep these in house, keep them run by public servants and we'll work with our members to make sure they are as efficient and effective as they can be."
He said anecdotally, the PSA hears from people that work in centres that are run privately.
"Our members who work in the council-run facilities, hear how they run, they run a lot less, kind to their workers.
"For the efficiency side of how well, they're run. It's a bit unknown at the moment. I haven't seen anything to say they are being run more efficiently."
Public engagement for council-run facilities had increased, he said.
"All their stats are going up, they're doing really well. They have a good Net Promoter score, which is how you measure customer satisfaction, they're hitting all their targets.
"It's a bit weird to say that the private companies can do it better."
He said council-run facilities were important to local communities.
"I think it goes to the local government. It's around the well-being or well beings. I like to go and think of them as part of the community hub of a community.
"If you go to any of these sites, which I did this week and last week, they are brimming with people, they're a centre for people to come, they socialise, they can get fit and active which I think we all need to do, its a hub of activity.
"It's a really great place for families to come. I've heard about queues that are outside some of our centres because they are so popular. It really goes to that hub of why we have community or community centres around Auckland, it's there for the community."
A statement from Auckland Council said no decisions had yet been made about who ran which sites or services.
The council will use an evidence-based approach to provide good advice to elected members for their decision making.
Under the proposal, council would retain ownership over access, hours and pricing and Aucklanders can expect that their local pools and leisure facilities will continue to operate as they do now.
The statement said: "We know that these services are highly valued by the community, and so they are highly valued by the council, too".
"The important thing for Aucklanders to know is that this review is not looking at any changes that could affect the way they use these services."