Prime Minister John Key has welcomed philanthropist Gareth Morgan to the political race but thinks he's got a tough job ahead of him.
"[It's] immensely difficult to get five percent. Doesn't mean it's impossible but it is really difficult," Mr Key told Paul Henry on Monday. "History shows you, the only time people have set up a party and really got there, is they've been an existing name like Winston Peters."
Mr Morgan, an environmentalist and economist, launched the Opportunities Party on Friday.
Mr Key said despite the challenges ahead, there is no way Mr Morgan will back down.
"Gareth likes the fight, he just likes the disagreement.
"Gareth is controversial, so if you think about what Gareth does, he goes away and finds something the most controversial he can because he quite likes the argument then he develops some research that supports him and then he gets in a bit of a row."
The Prime Minister said that Mr Morgan's polarising views could work against him.
"He won't be able to help himself but tell the country he is going to eradicate cats. Well, that's going to get Moonbeam's owner out of voting."
Mr Morgan is well-known for his anti-cat campaigning, referring to the animals "serial killers".
In a video launching his new party, Mr Morgan said: "The beef I have with establishment parties and career politicians is they try to do as little as possible,"
That anti-establishment stance is something the party might try to play on in the wake of Brexit and Donald Trump's political success.
However Mr Key believes the Opportunities Party is leaning to the left, more because of Mr Morgan's dissatisfaction with those parties than with politics as a whole.
"The policies, so much as they've named them, sound a little like he is left-orientated and not right to me, because he is talking about poverty and closing the gap and things we might hear Labour and the Greens talking more about."
Less than 24 hours after its launch, the Opportunities Party managed to secure more than 1000 paying members. That's enough to register the party with the electoral commission.