Prime Minister John Key says he supports the decision of some of his ministers to take their partners overseas with them.
ACT party leader and Local Government Minister Rodney Hide is defending the $25,000 tab taxpayers will pick up after his girlfriend travelled with him on an overseas trip.
Mr Hide is well-known for his criticism of MPs' perks, including the travel discount he used to pay for most of his partner's trip.
Mr Key says it is ultimately up to individual MPs as to whether they will use the travel discounts for their partners.
He says there is now an open and transparent system, and any MP who makes that decision must do so in the knowledge it will become public.