If the National Party wants to lead the next government it needs to get used to scrutiny, the Labour leader says.
It comes after the New Zealand Council of Trade Unions put out an ad campaign about National's leader Christopher Luxon, saying he was "out of touch" and "too much risk".
Deputy leader Nicola Willis told First Up the "attack ad" was nasty and personal, but Labour's Chris Hipkins said Luxon needed to get used to it if he wanted to be the next prime minister.
"If the National Party wants to be the government after the election, you get scrutinised and you get criticised every day," he told Morning Report.
"I have been every single day since I became prime minister, much of it from the National Party. That's just the nature of the democratic system and it's not actually unhealthy."
When asked if Hipkins agreed with the way Luxon had been portrayed in the ad, he said the ad was nothing to do with the Labour Party.
When pressed on it, he said he did not think criticising someone for things they had said and policies they had was a personal attack.
"Christopher Luxon called low income New Zealanders bottom feeders and went around the world calling New Zealand a wet, whiny and negative country. I think people can form their own judgements about who's being negative."
NZCTU president Richard Wagstaff said it had launched the campaign because it was "very concerned" about what it would mean for working people if the National Party were in power.
"I think the criticisms from National are trying to divert attention away from the issues. CTU is independent from the Labour Party, we don't even mention the Labour Party in the ads. It's our idea, we did it, and it's got nothing to do with the Labour Party."
Wagstaff told Morning Report CTU was happy with how the campaign was going. It had attracted a lot of attention and it felt it was their job to draw attention to what the National Party was offering.
"Those things very much concern us so we see it as our job to point these things out and take out an ad campaign to do so."
But despite CTU confirming Labour had no part in the ad, National's Nicola Willis said it showed Labour were running a campaign of negative, personal attacks.
"They're [the ads] not about the issues in this election or the challenges facing the country or what's lying ahead. Instead, these are attacks that are clearly very much negative, nasty, personal, and of course we can take it.
"National and Chris Luxon can take 41 days of personal attacks if that's how Labour and the unions want to run the campaign, but the country can't take another three years of a Labour government, so our focus is simply on a campaign that focuses on policy and issues and Labour are clearly taking a different approach."