Judith Collins defends her fake news tweet to Jacinda Ardern

National leader Simon Bridges is unfazed after MP Judith Collins took aim at the Prime Minister and misfired, using a well-known fake news website to make her point.

Mr Bridges says Ms Collins' sentiment was right, even if her method was not.

She had challenged a newly-returned Jacinda Ardern to denounce French child abuse laws, tweeting an article to hammer home her point.

The problem was it was taken from a website famous for fake news and conspiracy theories - home to articles claiming Katy Perry is a cannibal and Justin Bieber a shapeshifter.

"I'm not worried about people saying it's not a legitimate website when it clearly is a website - but is the story legitimate or not?" Ms Collins said.

"It seems that the story is legitimate."

The story is indeed based on fact: France doesn't have a legal age of sexual consent, and when it recently tightened child rape laws, a proposal to set the age of consent at 15 was voted down.

Other elements are less realistic, such as claiming the laws are a campaign by liberal activists to legitimise paedophilia around the world.

"There certainly are some concerns that I have about that sort of behaviour," Ms Collins said.

When asked about the article, Prime Minister Ardern told media that she likes to take her time before responding to stories that could be fabricated or embellished.

"I think we should all be concerned about fake news," she said.

Fake news is a relatively new phrase referring to made-up news stories. It was given prominence after the use in the last US election, and is frequently used by US President Donald Trump to describe media he doesn't like.

National leader Simon Bridges half-chastised, half-praised Ms Collins for sharing the dodgy article.

"It's wrong and that's clear - it's an issue she does feel strongly about. In general we should get these things right, but we don't always - particularly on Twitter."

It's not the first time Ms Collins has had trouble with twitter, once quitting after becoming embroiled in tweet wars.

But Mr Bridges denied that she needs a break from the social media platform, and Ms Collins herself clearly isn't bothered, as the tweet hasn't been taken down.