Defence Minister Ron Mark has threatened Mark Mitchell after the National Party defence spokesperson accused him of making personal use of NZDF aircraft.
It was revealed on Wednesday Mr Mark had been picked up and dropped off from Masterton several times while attending engagements as Minister of Defence.
At one point he flew from Masterton to Waiouru, which would only have been a three-hour drive.
Speaking to Lisa Owen and Ryan Bridge on RadioLIVE Drive, Mr Mark defended the flights, saying it was just easier to take the aircraft - and denied he was taking them to visit his Carterton home. Carterton is a 15-minute drive from Masterton.
Mr Mitchell called it a huge waste of money at a time the Defence Force was being asked to tighten its belt.
"I want to know why the Minister has either requested this service, or refused to decline it, as he would have known there is no way the flying hours, fuel and cost could be justified," he said.
However Mr Mark said it was unfortunate Mr Mitchell had criticised the flights, and thought his opponent would be above such an attack.
"I'm just really disappointed with Mr Mitchell - I thought he was better than that," he said.
"I guess that's what happens when you go to opposition and you were a useless Minister of Defence in the first place."
Mr Mark says he never asked for the flights, but they were offered to him and he accepted.
He's now going to look at all the previous uses of military aircraft by former ministers, and believes Mr Mitchell should be worried.
"What I will do is run a benchmark across all use of military aircraft over the last 10 years, and I'm already receiving messages that actually there's some interesting stuff in there," he said.
"Let's put it out in the media, and let's hope Mr Mitchell isn't embarrassed."