Opposition leader Simon Bridges has announced his plan to convert Jacinda Ardern's baby daughter to the National Party.

Appearing on Radio Hauraki's breakfast show on Friday morning, Mr Bridges denied hating the First Baby - but admitted it wasn't much getting him much press attention.

"Look, I don't think it's going to do a lot to help my poll ratings," he told hosts Matt Heath and Jeremy Wells.

"I don't hate it. Hate's a strong word."

The hosts then asked Mr Bridges if it's politically correct to have a female baby and if it should be considered genderfluid instead.

"Only under a Labour government," he replied.

"She should be going to school like in boy's clothes right?"

Mr Bridges suspects the baby has already cost the country "a lot" of money after its birth in a public hospital, and plans on converting it to a National supporter.

"Her grandfather is a cop, right. He knows what you need out there to be keeping people safe. And just because there's pinko ideas in the parents it doesn't mean the baby's taking those on board," he said.

"Cops vote blue. They know that we're strong on law and order. So Jacinda went to uni, she got some funny ideas. That baby gonna be spending a lot of time with her grandparents.

"You spend too much time in universities, you get funny ideas."

Newshub.