Michael Wood has dismissed questions from Newshub national correspondent and AM fill-in host Patrick Gower about Clarke Gayford going to Antarctica with his fiancée Prime Minister Jacinda Ardern.
On Wednesday, Ardern and Gayford departed for the icy continent to mark Scott Base's 65th anniversary.
But questions were raised about Clarke's presence on the trip. AM fill-in host Amanda Gillies on Friday questioned: "What the hell is Clarke doing there for?"
When asked by Gower about Gayford attending the trip, Labour minister Wood said it was "entirely appropriate".
"It's common practice," Wood said.
The same thing happened under former Prime Minister Sir John Key, Wood added. Sir John's wife Bronagh accompanied him on a trip to Antarctica in 2013, while ex-PM Helen Clark's husband Peter Davis went with her in 2007.
Ardern said this week she checked before the trip Gayford accompanying her wouldn't displace any scientist given there are only limited beds available at Scott Base.
"When we were looking at, of course, the logistics around the trip and the numbers that were allocated to our team, I was aware that in the past, certainly in recent memory, Prime Ministers who have had the privilege of travelling have brought their spouses," she told a reporter.
"Before we committed to doing the same, we checked that it would not displace any scientists, any researcher, anyone who is part of the redevelopment work.
"Essentially because we're sharing a bunk, we weren't displacing anyone. That was key for us in making that decision."
It took two attempts to get Ardern to Antractica this week. Her flight on Tuesday was turned around due to bad weather, delaying her trip to Wednesday.
New Zealand was one of the only countries in the world which maintained a territorial claim, base and heritage responsibility in Antarctica.
"Antarctica is part of New Zealand's heritage and future and we’re committed to its protection as a natural reserve for peace, science and co-operation," Ardern said last week ahead of the trip.
"Antarctic research is urgently needed to understand past and future climates, how we are affecting Antarctica, and how Antarctica will affect us."
