Te Taura Whiri i te Reo Maori is calling on speakers of te reo to create a gigantic Maori language zone during Te Matatini 2015.
"With thousands of speakers gathered in one place at one time, we urge those attending Te Matatini 2015 to use Maori language day in and day out," acting chief executive Poia Rewi said.
"Let's create the biggest Maori language event."
The Maori Language Commission will be distributing complimentary hats, bags, water bottles and stickers adorned with the words "Korero Maori mai - speak Maori to me".
"The invitation is to speak Maori right throughout the festival and beyond. We invite and challenge people to use te reo Maori as much as possible during Te Matatini 2015, from the powhiri to the finals, and beyond," Mr Rewi said.
"Leading up to the festival, the 45 kapa haka groups will hold at least 100 wananga or rehearsals. There is huge potential to create increased and/or full Maori language immersion environments for te reo Maori, where this is not the practice already."
The commission hoped that whanau would take the "korero Maori mai" invitation home with them, too.
Maori speakers can use the invitation to identify other speakers and strike up conversations in te reo Maori anywhere - on the bus, in the street and at work.
The Maori Development Minister also encourages whanau heading to Te Matatini to use as much Maori language as they can.
"If we're serious about the survival of Maori language, we'll take every opportunity we can to use it. Te Matatini is that perfect opportunity - thousands of whanau, four days of topnotch kapa haka and lots of korero," Te Ururoa Flavell said.
According to Census 2013, more than half Maori adults can speak some te reo Maori and one in five can hold a conversation in te reo.
Mr Flavell, who will attend most of the festival, said whanau Maori needed to rise to the challenge if the language was going to survive.
"We know it takes one generation to lose a language and three generations to get it back so I applaud the Maori Language Commission for challenging us to speak as much Maori as we can while we're at one of the largest Maori events on the calendar."