The latest Covid measures could see household contacts of a positive case isolating for 24 days.
The plan's designed to slow the spread as we get ready for Omicron, but there's concern the plan will quickly become unworkable.
New rules, introduced on Friday, mean positive cases must isolate for at least 14 days, including 72 hours symptom-free.
However, household members need to be in isolation for an additional 10 days after the positive case has been cleared.
That means household contacts will have to isolate for at least 24 days or three and a half weeks, which is longer than the actual case themselves.
ACT Party leader David Seymour said the new rules would be impractical.
“These rules mean that if you get a positive test, then your household can be out for a month. People who can't afford that just won't get tested, defeating the purpose.
“If people do follow these isolation rules, then we're going to have serious problems with healthcare capacity and supply chains.”
In a statement, the Ministry of Health told 1News there was a workaround that households could use.
The ministry said a positive case could isolate in separate accommodation, away from other household members. This would mean household members would only need to isolate for ten days. If households can’t find new accommodation though, then it’ll have to be for longer.
Dr Bryan Betty of the Royal NZ College of General Practitioners said he foresaw the periods being reduced in an Omicron outbreak.
“I suspect as Covid becomes established in the community and we have a number of cases across New Zealand… [then] what I see happening is those periods of time being reduced.”
Health officials said the new isolation periods are under review and will change in response to new outbreaks.