Green Party co-leader Russel Norman is being criticised for offending the Chinese Vice President Xi Jinping.
Foreign Minister Murray McCully says Norman should have been respectful when he protested on parliamentary grounds but civil rights groups claim the comments undermine a politician's right to freedom of speech.
"I find it massively disappointing, of course we have freedom of speech in New Zealand, but that doesn't mean we use that freedom of speech to cause offence to people," says McCully.
Members of the public who protest are only allowed as far as a certain point on parliamentary grounds but Norman has parliamentary privilege so as a politician he was able to protest just an arms length away from the Chinese Vice President.
It is this privileged position McCully claims was abused and he says Norman's actions were calculated to give offence.
"When we have differences of views with other countries and we do frequently, I think it's important that we express those views in a way that is respectful and courteous," he says.
"What I'm saying is that Dr Norman shouldn't have actually been in that situation in the first place, if he'd have shown good judgement and if he'd put New Zealand's interests to the fore."
Politicians protesting is hardly anything new.
The late leader of the Greens, Rod Donald, held up the Tibetan flag when China's Chairman visited in 2005, prompting him to take another route into parliament.
Political commentator Chris Trotter says New Zealand's relationship with China is a very important component in the country's future prosperity.
"So while he was exercising his rights I am not altogether sure that Mr Norman was exercising his responsibilities," he says.
Norman says the government has failed to stand up for free speech and human rights in its failure to control the Chinese security services in New Zealand and failure to speak out for human rights and democracy in Tibet.
"On the face of it, it looks like the government is going quiet on human rights because they think they might be able to sell some more milk powder as a result.
"I think we should be extremely cautious in our dealings with China because it is a dictatorship and has very strong anti-democratic and anti-free speech views and is getting increasingly aggressive about promoting those views," he says.
New Zealand needs to be careful not to become one of China's agents, Norman says.
He says McCully's call not to use freedom of speech where it will cause offence means there is no free speech.
"New Zealanders believe in free speech and democracy."
The New Zealand government should speak out about the situation in Tibet, Norman says.
"The Chinese government has imprisoned people just because they speak out in favour of Tibet, they've murdered people in Tibet."
The Speaker of the house will be reviewing the tussle this week.