Judith Collins says kindergarten children shouldn't be taking part in Friday's School Strike 4 Climate marches.
Kids across the country - and around the world - are skipping classes to protest inaction on climate change.
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In the small Bay of Plenty mining town of Waihi, students from primary schools and Waihi College will be joined by toddlers from Waihi Kindergarten.
Head teacher Kate Mullaney told NZME while taking part is "totally optional", none of the parents have pulled their kids out of the historic demonstration.
She said the kids understand exactly what they're protesting - saving the environment for their own futures.
But National MP Judith Collins doubts it.
"Let's just be sensible about this - I hate the thought kindergarten kids are being used for political purposes," she told The AM Show on Friday.
"If it was my kid being told 'you've got to go and save the planet today' by the teacher, I'd remove my child from that sort of behaviour. Don't use our kids like that. Let three-year-olds be three-year-olds."
Collins last week said while high school students might have genuine concerns, "their little protest is not going to help the world one bit".
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Asked by host Duncan Garner what she'll be doing instead of joining the demonstrations, Collins said she'll be going to Christchurch, "flying there using fossil fuels".
Asked if she'll plant a tree to offset the carbon emissions, Collins said she'd "probably look at a tree".
In contrast, Labour MP Kris Faafoi said if the parents are okay with their little ones being taken on a protest, then he's okay with it.
"My parents came from a very small low-lying Pacific Island [Tokelau]... if it can give those young people a voice because they're worried about the place where their parents and grandparents grew up, then all be it."
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Swedish teenager Greta Thunberg, who kickstarted the children's climate protests when she chained herself to her country's parliament last year, has been nominated for the Nobel Peace Prize.
Scientists say hundreds of thousands of species face extinction if the world warms the projected 2degC by the year 2100.