Christopher Luxon's staying tight lipped about coalition discussions.  

Meanwhile, ACT's David Seymour says he's happy to make the coalition agreement public once it's been struck.  

Arrangements in 2017 weren't made public by Jacinda Ardern, with the Chief Ombudsman ruling details couldn't be requested under the Official Information Act as it came within her capacity as Labour leader.  

Former National Health Minister Jonathan Coleman told Kate Hawkesby that historically, it's always happened behind closed doors. 

He says negotiations are always kept private, and even in retrospect no one really knows what went on and why things were negotiated. 

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