Chinese will be the third most common language spoken in New Zealand if the NZ Chinese Language Week Trust has its way of counting Chinese language speakers.
Trust co-chairman Raymond Huo said, besides Mandarin, it is wrong for Statistics New Zealand to consider different Chinese dialects as independent languages.
Mr Huo, a former Labour Party spokesman for statistics, said the ranking order of English, te reo Maori, Samoan and Hindi as the top four most spoken languages in New Zealand by Statistics NZ was "incorrect, misleading and deeply flawed".
"Treating Mandarin, Yue or other Chinese dialects as independent languages is deeply flawed," Mr Huo said.
"It is similar to making statistical inferences about the difference between Northern English, Oceania English and Indian English, or ... between pub talk and the King's English.
"As such, English may not be the most widely spoken language if each 'dialect' was treated as an independent language as in the case of Mandarin and Cantonese."
Census general manager Denise McGregor said the goal of the census was not to rank languages in order of popularity.
"But rather to build a picture of who speaks particular languages, whether they speak multiple languages, their ages, their birth places and much more."
The Census 2013 question asked: "In which language(s) could you have a conversation about a lot of everyday things -- English, Maori, Samoan, New Zealand Sign Language and other language(s), for example Gujarati, Cantonese, Greek?"
Mandarin is the official language of China and Taiwan and one of the four official languages of Singapore.
The Chinese written script is broadly the same, but a single character can be pronounced in over 1000 different ways across China, according to Mr Huo.
Mrs McGregor said having a similar writing system did not necessarily mean they were the same language.
"Just as we would not call Korean or Japanese 'Chinese' just because they are written in that script," she said.
Mrs McGregor said it was important to have a system of classification that enabled languages to be either grouped or looked at individually.
"It's incredibly useful to know that in a school zone, or at a specific library, or on a particular bus route there will be people who speak specifically Mandarin or Chinese," she said.
"Just knowing they speak 'Chinese' isn't likely to be as useful in targeting services."
In the last Census, 52,263 people spoke Northern Chinese which includes Mandarin, 44,625 spoke Yue that includes Cantonese and 42,750 spoke a "Sinitic" language.
Mrs McGregor said of the 171,204 people in New Zealand of Chinese ethnicity, 45,216 were born here.
"The majority of these people do not speak any language other than English," she said.
"We think the rich picture of the different Chinese languages and dialects is a valuable thing to have."
David Soh, editor for Auckland-based Chinese language daily Mandarin Pages, said the Census figures for Mandarin speakers were "too low" to be correct.
"The figure that just over a quarter of the Chinese population are Mandarin speakers sounds too low to be accurate or true," Mr Soh said.
"The fact is Chinese who speak Chinese dialects are often also able to converse in Mandarin, but the Census figure doesn't seem to reflect that."
AUT's head of the School of Language and Culture, Sharon Harvey, said linguists would consider Chinese dialects as independent languages.
"It suits the Chinese Government to say all these languages are 'only' dialects but most linguists would say many are languages in their own right."
Cantonese is a language with nine spoken tones but in Mandarin there are four, said Dr Harvey, and it would be hard to learn Cantonese and "make all those sounds" if someone hasn't learned them as a child.
NZ CHINESE BY NUMBERS
• 171,204 -- population total
• 122,964 -- speak at least one or more Chinese languages
• 45,216 -- NZ born, most speak only English
• 52,263 -- speak Northern Chinese, including Mandarin
• 44,625 -- speak Yue, including Cantonese
• 42,750 -- speak a Sinitic language without further defining
(source: Census 2013)