The Act party says voters shouldn't underestimate its role in Parliament.

The party's relaunch at the weekend introduced new policies, including a repeal of parts of the Human Rights Act that deal with speech inciting racial disharmony.

Leader David Seymour hopes that the party can bounce back from several elections of low popularity, and is aiming to have 14 MPs after the 2020 election. 

He told Mike Hosking that he believes National would get behind his ideas should they be in a position to win the election, with charter schools evidence of that. 

"Act, with only one MP, made it happen. And today, if you ask the National Party, they'll say it's the best idea they ever had."

Seymour also cited his assisted dying bill, which will be voted on again next week. 

"I think people who vote for Act get more bang for their buck in terms of changing New Zealand then any other vote they could cast." 

He says it was "hugely unfortunate" how his free speech bill was reported on, saying that it was unhelpful to national harmony. 

"It's highly offensive to many New Zealanders to think that the basic idea of being able to say what you like and never be suppressed by a government so long as you are not inciting or threatening violence is critical to our society."