Justice Minister Andrew Little is standing by the $1.5 million cost of last month's criminal justice summit despite a budget blowout which has been criticised by Prime Minister Jacinda Ardern.

The final cost of the summit which brought together 600-700 people in Porirua to discuss the justice system and its future direction was more than double the $700,000 Little originally estimated it would cost.

Ardern was asked about the budget blowout by reporters today.

"My expectation is that when we set a budget, we stick to it," she said.


But Little defended the cost.

"I'm totally satisfied with the cost of the summit. It was a two-day summit. It was several hundred people. It takes a lot to put that together and to run it in a way that makes sure all the voices are heard."

Told that Ardern had criticised the budget over-run, Little said: "I stand by what the justice summit has achieved. It's done some good things.

"This is a community of people from all parts of the sector who have not been engaged in the future of our corrections system for the best part of 20 years and they needed an opportunity to have their say.

Little is expecting a breakdown of the cost.

National's Justice Spokesperson Mark Mitchell said earlier this week that the money would have been better spent on victims.

He said the food for the summit's attendees included a "decadent gluten-free chocolate brownie, pork, apricot and thyme pastries, four different kinds of croissants, luxury pies and chicken and cranberry casserole".