Labour says specialist squad plan a sign police are underfunded.
A reshuffle of the country's special tactics group could result in staff numbers being slashed in Wellington and Christchurch as more resources are moved to Auckland.
Sources have told the Herald of a proposal by New Zealand Police to reshuffle the number of STG members distributed throughout the country. It was understood Auckland would receive more staff and Christchurch and Wellington would lose staff - with nearly half of those in Christchurch set to move north.
The Herald understands the possibility of the changes was causing concern among staff and community members.
Police Operations Support Commander Inspector Geoff Jago confirmed the STG's deployment was under review.
"Police continues to review its staffing deployment across the organisation as appropriate to ensure we are best placed to meet operational demands," he said. "This includes an ongoing review of the STG, which has squads based in Wellington, Auckland and Christchurch.
"However, we stress that no decisions have been made about the group's future structure.
"That said, it is important to note that regardless of their physical location, STG squads by their nature are highly mobile and well-equipped to respond to incidents anywhere in the country at short notice, based on demand."
Labour's police spokesman Kelvin Davis said the move was another example of budget restraints hampering law enforcement.
"There needs to be the full team based in the South Island and it really shouldn't happen - it's a [funding] cut, the police are being under-funded."
If more staff were needed in Auckland, it should not mean less protection was at hand elsewhere, he said.
"They say they can dispatch people from wherever down to Christchurch in the blink of an eye, but I don't think that is much comfort to people down there who need a special tactics group in the blink of eye, not in an hour's delay."
He said the issue had been raised by constituents concerned about the impact of fewer STG staff available not only to Christchurch but also to the whole South Island.
A spokesman for Police Minister Michael Woodhouse said decisions around police deployment were the responsibility of the Police Commissioner.
"However, police have advised [Mr Woodhouse] that the review is all about making sure STG resources are best deployed in the places they are needed most, and has nothing to do with budget considerations."