Furthermore, Maori Party leader Pita Sharples said he was unsure if any MPs should attend the hui as it was a matter for iwi leaders and claimant groups to work out.
Angered by both of these comments, Mr Harawira vented on Facebook.
"Time John Key realised a few home truths like (1) he can tell his little house niggers what to do, but (2) the rest of us don't give a s*** for him or his opinions."
Later in the post Mr Harawira suggested public pressure would force the Maori Party to send a representative to the hui but they would have to ask for John Key's permission.
Responding to questions from the Bay of Plenty Times, Mr Harawira said he had not directed his comments at the Maori Party leaders and people could draw their own conclusions about who he was talking about.
Mr Harawira acknowledged that many people would find his choice of words offensive, but said Mr Key's behaviour was also offensive.
"I think it's unacceptable for John Key to try to argue the ruling of the tribunal. I think it's wrong for him to speak so disparagingly about the tribunal."
"Maybe he needs to apologise about the way he's treated Maori, maybe then I'd consider apologising for my language."
Finishing his coffee, Mr Harawira said he was only in Tauranga for the day.
"I understand Simon Bridges is keen on attending [the hui] so I've come to see if he'll come."
Ngati Ranginui iwi board member Tommy Kapai Wilson said he did not believe Mr Bridges would attend the hui and Mr Harawira was just "milking the media".
"All the Mana Party is is a protest party, they're not at the table. The reality is the Prime Minister will deal with the iwi leaders."
"The Mana Party and the Maori Council are like a cold kumara in a hot hangi. This [hui] is the Maori Council's swansong."
Maori Party MP Te Ururoa Flavell called Mr Harawira's choice of words a "Honeism".
"We don't pay much attention to Hone's comments because most of the time it is untruthful ... if we worried about what Hone Harawira said at every turn we'd feel quite annoyed all the time."
Mr Bridges could not be contacted for comment last night.