Man, myth, Miley Cyrus fan - whatever he is, ACT leader David Seymour has had quite a week.

He's told students with mental health issues to "harden up," he's asserted that the French "love the coq," and he's urged a delay on the flag vote, so kids and parents can argue about it at Christmas.

But this is hardly Seymour's first press conference. With Winston Peters turning 70 this year we need a politician making these kind of headlines, and 32-year-old Seymour has been his heir apparent for a long while now. Like Peters (who he's not frightened to send up), Seymour's got a sense of humour - and he's quick to use it.

DAVID WHITE/FAIRFAX NZ ACT MP David Seymour in his Bowen House office.

Seymour entered public life repeating the word "hi" six times in a row, starring in 2014's most talked about political campaign video.

With all the charm of a nine-year-old forced into this by his overbearing mother, ACT's then-candidate for Epsom explained his remarkable, surely unique skill of knocking on doors in New Zealand's richest electorate.

But youthful awkwardness was something of a breath of fresh air in the ACT Party, which was just coming off a half-decade featuring John, Don, and Jamie.

Seymour didn't seem to have a dog whistle so firmly lodged in his mouth, and he brushed off the negative reaction to the video with aplomb, tweeting that "the thing about making a viral video is you never quite realise when you're doing it."

He won the seat easily and was soon ACT's only member of Parliament.

(Epsom has long been one of New Zealand's most "interesting" electorates, as National routinely hand it off to an ACT MP in a complex little dance of MMP trickery. But that's neither here nor there.)

As Parliamentary Under-Secretary to the Minister of Education and Minister of Regulatory Reform, Seymour has continued ACT's drive back towards populist libertarianism. He's helped move charter schools and RMA reform forwards, as well as drafting a private bill legalising euthanasia.

Yet he's probably gotten the most headlines out some slightly less serious governing - it was Seymour who secured every Kiwi's right to buy booze at whatever the time the rugby was on.

With all that under his belt, it's no surprise Last Week Tonight host John Oliver is keen to have him on.