Former Māori Party co-leader Pita Sharples says Te Reo Māori should be compulsory in schools - at all levels.
The language is dying and it "would be devastatingly expensive not to do it", he told Duncan Garner on The AM Show on Thursday.
The comments come after incoming Education Minister Nikki Kaye said she expects a "healthy debate" about making Te Reo Māori compulsory in schools at the coming election.
But she says a change in policy would depend on if it could be properly resourced.
"We are losing the language forever, soon," Dr Sharples warned.
"We are the only country that hasn't looked after the indigenous language. And worse than that - we blatantly misuse the language."
Dr Sharples was the Minister of Māori Affairs and Associate Minister of Education in the National-led Government 2008-2014.
During his time in Parliament, he campaigned for making it compulsory to offer Te Reo Māori in schools.
Now he says Te Reo should sit "a little bit in front" of other core subjects such as maths and English, and be learned by all students.