Supporting Prime Minister Jacinda Ardern is what Grant Robertson is focused on.

He's taking on the role of Deputy Prime Minister.

He told Heather du Plessis-Allan it's a big honour to stand in for Ardern when she can't be there.

"That's something I have enjoyed doing as Finance Minister, and I really look forward to doing that in other ways as deputy Prime Minister."

He says it's important for the rainbow community to see members taking on big roles - like Deputy Prime Minister.

Robertson - who's openly gay and is the first LGBT person to be in the role - says that's particularly true for younger members.

He says he's tried to be a Finance Minister for all Kiwis - and that will continue in the new role.

"I still get a lot of emails and letters from young gay, lesbian, bisexual and transgender peeple, who look towards us to provide that kind of role modelling." 

As well as Deputy Prime Minister, Robertson will also be the Minister of Finance, Infrastructure, Racing and Sport and Recreation.

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