One of the KiwiRail shareholding ministers says there are good reasons for the InterIslander ferry service to stay in government hands.
The coalition last year canned a replacement project for the ageing fleet, but it has also lambasted the way KiwiRail, which owns InterIslander, has maintained the vessels.
After the Aratere grounding on Friday, National Road Carriers Association spokesperson James Smith said the government should leave business to the business sector.
"Get out of running ferries, stick to regulation and policy settings and let commercial operators take over."
Finance Minister Nicola Willis told First Up Bluebridge were doing a good job but it was in people's interest to ensure they had a competitor and to ensure there was enough capacity for travel across the Cook Strait, for passengers and freight.
Unions and opposition parties have also criticised Willis for cancelling the contract for new ferries after the budget blew out to nearly $3 billion, and accused her of "dragging her feet" on a plan B.
Willis told First Up she did not regret the decision to cancel the new ferries, because those ships were problematic. They also were not due to arrive until 2026 so would not have solved the Aratere problem last week, she said.
"That proposal was problematic in lots of ways, they were going to be really large ships, considerably larger than the current ones, which meant the berths at both Picton and Wellington weren't big enough to fit them and were going to require a huge amount of work.
"It also meant that there were safety questions being raised about whether such big ships would be manoeuvrable enough in the narrow channels of the Cook Strait, as it's coming into the Marlborough Sound.
"What we've done is we've said let's get a workable proposal that's practical, and we totally accept that, of course, we're going to have to replace the existing ageing ferries, that is the case, but none of that stops the fact they should be maintained and operated safely and reliably in the current make-up."
KiwiRail had been advised they could safely operate the current ferries for some years to come, she said.
"You can also have certainty that the government is working on the best replacement option for those ferries, that we have funding available to replace them, and that we're working through a plan.
"We've been given advice by an expert advisory group that we're working through. That advice gives us confidence that we can get appropriate ships built in a timely way."