The Act Party is languishing in the polls at around 0.3 percent, but its electoral lifeline - the Epsom seat - will almost certainly guarantee David Seymour will return to Parliament.

Photo: VNP / Daniela Maoate-Cox

Voters in the wealthy Auckland seat are well-versed in voting strategically to prop up National governments, and they look likely to do it again.

Back in 2014, Mr Seymour was a first-time candidate and political newbie - he won Epsom by a margin of over 4000 votes.

Three years later, he's a familiar face to the voters of Epsom, and with National giving him the nod again, it's likely Act will keep the seat its held since 2005.

But he admits he hasn't knocked on as many doors as he did last time around.

"It's mainly because I've had two jobs, four jobs actually, if you count Act in Parliament and then being in government and an Epsom MP. Whereas last time I was full time as a candidate."

Mr Seymour said voters in New Zealand's wealthiest electorate were worried about a range of issues.

"Six months ago it was immigration - for whatever reason that seems to have stopped entirely.

"I suspect it's partly due to the fact that the Waterview tunnel has been absolutely transformational to this whole area, and congestion is reduced and people are less worried about that now."

"But generally speaking it's school zones, congestion which has reduced along with immigration and for a lot of people it's maintain the government that is not going to spend a lot or destabilise the economy."

Act is polling at 0.3 percent according to the latest RNZ Poll of Polls.

Winning the Epsom seat is crucial to Act's survival, but is there really any contest?

More than 60 percent of the party vote in Epsom goes to National but the party has given to the nod to Mr Seymour for the seat.

National candidate Paul Goldsmith said his focus was on growing that vote, and he's not actively telling voters not to vote for him.

"I always say, look it's entirely up to them who they vote for. We've indicated that we are happy with the ACT candidate having the electorate but we are very focused on the party vote."

And what do the voters think?

On the streets of Remuera, all but one person RNZ spoke to was giving their electorate vote to David Seymour.

"Because they're the only economic party," one man said.

Others were voting for him because they "liked him" and he had done a good job over the last three years.

Labour's David Parker and the Green Party's Barry Coates are also standing in Epsom, but like Mr Goldmsith, they're running party vote focused campaigns.