Gareth Morgan says his reaction to Labour's surge in the polls after Jacinda Ardern took over as leader was to think voters "cannot be this thick".
"It took wind out of everybody's sails. When 20 per cent of the population moves in 24 hours on a smiley face. You look at it and you go - 'Jesus, they cannot be this thick'."
Morgan has almost lost his voice and told the Herald he's "pretty shagged" - and unable to say how he thinks his political party will fare on Saturday.
TOP will need to get at least 5 per cent of the party vote to enter Parliament.
"We just did our 80th town hall last night in Christchurch ... that's what I do every night ... I'm in a bit of a bubble in a way because I get people all over me. It's very easy in that position to say, 'Oh the whole world is going to vote for me'. So I just don't feel that I am in a position to gauge reality.
"I see [TOP's position in polls] at 2 per cent, steady. Then I'm surrounded by nothing but positivity by young people, and I'm supposed to make a sensible judgment out of that? No idea. I've got no idea. What will be, will be."
Morgan said Ardern taking over as Labour leader had made life difficult for other parties, but things had settled since then.
"And I think it was just a euphoria that at last Labour were going to be stepping forward, as opposed to being angry about everything. Which is where Andrew [Little] was.
"I just think it was that sense of political relief. So good on her. Awesome - she has captured the mood and has made absolutely a contest out of it. She might even win it."
Morgan has been strongly critical of New Zealand First leader Winston Peters, describing him as "nothing more than an Uncle Tom" because of his stance on the Treaty of Waitangi and Maori seats.
New Zealand First has dropped support in recent polls, but could still decide the next government. Morgan said Peters "looks to me to be imploding".
"Which is what I bloody pray for ... I think what has been really interesting is essentially the demolition of Winston."
Morgan said he has spent about $3 million on TOP's campaign, and had invested in the Morgan Foundation for many years beforehand, which had helped for the base for policy development.
He said the policy people had engaged with most was TOP's tax policy, which would expand the definition of taxable income to include a minimum rate of return from productive assets - including houses.
Another lesson from setting up a new political party was how disconnected political media and commentators were from New Zealanders, Morgan said.
Whatever happens on Saturday, Morgan said TOP would continue beyond the election.
"I think the TOP community is too big now for it to be the end. We've got 800 volunteers, 40,000 people on the email. They are big numbers. We have 4000 paid subs or something like that.
"I don't think it's the end of TOP at all. I have deliberately said to myself to focus on getting the shop to Saturday. Then on Sunday and Monday you start thinking about what next."