A former Deputy Prime Minister disagrees the role's largely ceremonial.

Prime Minister-elect Chris Luxon has confirmed policies have been settled in Coalition talks - and negotiations have turned to ministerial roles.

ACT's David Seymour made a public pitch for Deputy, but Luxon has downplayed the role's importance.

Sir Don McKinnon was the deputy to Jim Bolger in his National Government, under the single-party system.

He says under MMP it can be someone from a different party, but the duties are real.

"You're there to do things that your leader, your Prime Minister, doesn't want to do, meet the people he doesn't want to meet, go to the places he doesn't get time to go to."

LISTEN ABOVE