Some officers who resigned rather than get a Covid vaccination have been seen protesting at Parliament, facing down their former colleagues on the frontline, the police association says.
The High Court on Friday quashed the mandate for police and Defence Force staff but it doesn't impact interal vaccination policies of the organisations.
The police association is expecting most officers stood down over Covid-19 vaccine mandates will return to work.
Association president Chris Cahill told Morning Report police would have to consider what work returning officers do as some may have been protesters at Parliament.
The roles they would do back on the force would also have to be considered from a health and safety perspective, he said.
Cahill said unvaccinated officers would be conflicted if there was any suggestion they were to police anti-mandate protests.
He said there was plenty of work for them in the regions.
Some would make a personal choice not to return, but the vast majority were "very keen" to return to work, he said.
"This ruling isn't about whether the vaccine is appropriate, it's saying whether their rights were impinged by a mandate and whether that impingement of rights was justified.
"It's an unusual ruling in a way, because there's so few officers both in police and defence, you're talking about 164 police that the courts looked at - it's probably really 131 now - because that's so few, it couldn't impinge on the police's ability to operate core services so you can't justify the breach of their rights."
The court case was successful because so many officers - 98.5 percent - did have their vaccinations, he said.
"These officers now are not stopping the high level of vaccination so lets get them back to work, they're needed, we're short staffed all around the country and I'm sure they'll be welcomed back."
Prime Minister Jacinda Ardern told Morning Report the government would take time to consider the ruling.
The judge made the call they're no longer justified but hasn't said whether mandates were needed when they were implemented, she said.
The National Party says the court's decision could provide an avenue for further challenges.
The ruling does not cover mandates for other workforces but National Party leader Christopher Luxon said it would come under close examination.
A senior lawyer told Morning Report the ruling wouldn't impact other mandates.
Hayden Wilson, specialist public lawyer and chair and partner of Dentons Kensington Swan in Wellington, said there were quite particular reasons for the decision, and the mandate was no longer justified.
The mandate wasn't focused on preventing the spread of Covid-19, unlike other mandates, but was to ensure continuity of service and public confidence, he said.
"This decision is very much focused on the justification that was used for this mandate."
The police and defence force were so successful of getting their staff vaccinated under internal policies that the court said it didn't have evidence that the mandate made a difference, he said.