Gareth Morgan standing behind 'lipstick on a pig' comment

The Opportunities Party (TOP) leader Gareth Morgan isn't backing down after calling Labour leader Jacinda Ardern "lipstick on a pig".

In a press conference on Monday, Dr Morgan cited Former US President Barack Obama's use of the same phrase in reference to the Republican Party's new slogan for "change". 

"I could've used any figure of speech, but I like that one because it's exactly what Obama said. I could have said something far more Gareth Morgan, like 'It's the same as polishing a turd'," Dr Morgan said.

"Changing the leaders is not sufficient to address the issues that New Zealanders are very upset about," he said. 

Labour leader Jacinda Ardern says she is not bothered by Dr Morgan's comments.

"I'm happy to add Gareth Morgan to our email list so he gets updates on all of our policy announcements because it seems like he's been missing out on them," Ms Ardern said.

When asked if she thinks this was misogynistic, Ms Ardern said she hadn't "sat down and analysed it".

Prime Minister Bill English has called Dr Morgan's comments attention-seeking. 

"If you've got an attitude like that I don't think anyone in public life would want to work with him. That is outside the acceptable boundaries of political criticism and language," Mr English said. 

After the inital tweet, Dr Morgan shared a photo of lipstick next to a mug featuring the face of former Prime Minister Robert 'Piggy' Muldoon.

Dr Morgan also sent out a barrage of tweets condemning "Jacindaphiles" for not focusing enough on policy.

On Sunday evening, Dr Morgan tweeted "Jacinda should be required to show she's more than lipstick on a pig. Will she be?"

Dr Morgan has previously said TOP would steer clear of attack politics and focus solely on policy.

The party spokesman rejected Monday's tweet was negative politics.

"It is policy politics and it wasn't personal and it wasn't gender. It was not a gendered attack and I'm surprised people think it is, given Dr Morgan's track record.

"He is unambiguous that this is not about personality politics.

"We have had no contact from the Labour Party asking for an apology."

Twitter users reacted largely negatively.

"Gareth Morgan's comments about Jacinda are despicable," wrote @lyn_mowles.

"Gareth Morgan would like us to all focus on policy. We should leave the personal attacks to him, apparently," wrote @HORansome.

"Gareth Morgan's interactions with the electorate are slapstick from a pig," said @ThomedySci.