Defence aircraft 'not an Uber service' - former Defence Minister Mark Mitchell

National MP Mark Mitchell isn't backing down on his criticism of Defence Minister Ron Mark's use of military vehicles for transport.

Mr Mitchell, a former Defence Minister, was tipped off about Mr Mark's alleged use of the Air Force as his very own "taxi service".

Documents released under the Official Information Act earlier this week showed Mr Mark had been picked up and dropped off from Masterton while attending engagements.

"If I was Ron I would probably just come out and apologise and say, 'It was wrong, it won't happen again,'" Mr Mitchell told The AM Show on Friday. "From what I understand, that's not the approach he's going to take."

Mr Mark has threatened to release 10 years' worth of aircraft records, saying he's been told there is some "interesting stuff in there".

"Let's put it out in the media, and let's hope Mr Mitchell isn't embarrassed."

Mr Mitchell says he won't be.

"When I was minister, I had Dairy Flat airfield, which was literally two minutes form my home. There was probably two occasions where I could have said, 'Can you just pop over the hill from Whenuapai, land at Dairy Flat and pick me up there? "It's a lot more convenient, saves me having to fight the traffic to get to Whenuapai.

"But not in a million years would I consider asking them to do that, and had they offered, I would have declined... they're not an Uber service for ministers."

He couldn't rule out other National MPs who served as Minister of Defence having done so.

"I'd be disappointed and very surprised if any National ministers had been asking the Air Force to provide helicopters or fixed-wing aircraft to pick them up from home."

High-ranking Labour MP Phil Twyford told The AM Show the Defence Force wouldn't be offering to ferry MPs around if it wasn't appropriate.

"It's not uncommon for Defence Ministers to ride in Defence vehicles or aircraft. We all know the Defence pilots need to get flying hours in. My assumption is if the Defence Force has offered it, it must have been appropriate," he told host Duncan Garner.

"Ron wasn't going shopping, he was on business. He was doing his job."

But Mr Mitchell said MPs need to understand not every Defence Force offer of a ride should be accepted.

"NZDF will bend over backwards to support the minister - that's the way they operate. I was disappointed to see Ron put it back on the Defence Force. This is his decision... he should have declined."

It reportedly costs about $1182 an hour to keep an Air Force NH90 helicopter in the air. The documents show Mr Mark used NH90s as well as B200 and C-130H planes.

Newshub.