Green Party co-leader and Climate Change Minister James Shaw spent the most of any government minister on international travel in the last quarter, according to expenses released today.

Shaw's $73,771 Cabinet-approved travel between October 1 and December 31 last year eclipsed Prime Minister Jacinda Ardern's $54,487 and Foreign Minister Winston Peters' $49,378.

The Greens' three ministers and under-secretary spent a total of $121,194 on international travel, $22,948 on domestic air travel, and $18,639 on surface travel. That figure includes VIP transport and the travel of their spouses and staff.

Shaw travelled to Europe in the last quarter for climate change events.

A spokesman said ministers' air travel emissions were offset when they flew Air New Zealand or one of its Star Alliance partners. Green MPs also offset emissions through a separate programme the party ran.

New Zealand First's four ministers and under-secretary spent a total of $114,467 on international travel, $34,727 on domestic air travel, and $58,680 on surface travel.

Defence Minister Ron Mark spent only a little less than Peters on international travel, on $48,373.

Labour's 22, including 20 ministers, an under-secretary and the Prime Minister, spent a combined $337,974 on international travel, with Ardern's travel the highest. Energy Minister Megan Woods was next highest on $51,459.

Labour spent $165,373 on domestic air travel and $238,273 on surface travel.
Other MPs' expenses were released today, with an explanation from Parliamentary Service on how VIP travel is calculated.

It was National leader Simon Bridges' $83,693 in VIP transport costs in the June quarter last year were the catalyst for the breakdown between the party and MP Jami-Lee Ross after they were leaked to the media early.

New disclosure notes issued alongside today's expenses reveal that Bridges is charged $171 per hour for VIP travel services while ministers are charged only $68 an hour.

Bridges' VIP transport would have been $33,281 if he had been charged at the same rate as ministers. That is still higher than any minister spent in that quarter.

Bridges' spending on VIP travel was substantially lower in the September quarter - $47,223.

While he spent $13,756 on VIP travel in the December quarter, that figure would have been only $8236 if charged at the ministerial rate.

A spokeswoman for Parliamentary Service the change in reporting had been made because the areas had been the subject of scrutiny.

"The problem was, in the past that people were comparing apples and oranges as Members and Ministers have different charge-out rates.

"In order to provide more clarity we have disclosed (as a note) what the cost would be if Members were charged at the same rate as ministers so that the cost would be comparable," the spokeswoman said.