He said he had that agreement in writing "and they still turned tail".
When contacted, he would not say whether it meant the end to his campaign but said he would make his position clear on Tuesday.
Maori Party co leader Tariana Turia said the party had spoken to Mr Henare very early on before they knew the Government preferred someone else and believed the Government should choose the Speaker.
Of Mr Henare's suggestion someone start another Maori party, she said it was a good idea: "He might like to revive the Mauri Pacific Party."
Although she and Dr Sharples had intended to meet with Mr Henare to discuss it, his tweets meant that was now unlikely.
The Speaker is voted on by Parliament and it is understood Henare was trying to persuade some of National's caucus that they did not need to vote along party lines to try to make up the numbers he needed.
Labour MP Trevor Mallard said Labour had not yet decided who it would support for Speaker. Asked whether he had given any undertaking to Mr Henare, he said "I told him if we made a difference to the numbers, I'd take it to caucus".
On Twitter, Mr Mallard had another job suggestion for Mr Henare, observing Mr Henare's old job was up for grabs again - as deputy leader of NZ First.