The Maori Party says opposition to a bill allowing the Treaty of Waitangi to be mentioned in legal oaths goes against the true partnership spirit of the Treaty.
In Parliament on Wednesday National, ACT, United Future and New Zealand First all voted down the bill.
Maori Party co-leader Tariana Turia says she is appalled by the result as it's counter-productive to what the Treaty was set out to achieve.
She says one of her party's kaupapa (philosophies) is about nation building using the Treaty of Waitangi as New Zealand's founding document.
Mrs Turia says the Treaty's about a relationship between tangata whenua and the British monarchy - not about legal issues.
She says the only reason why it has become a legal issue is because of the Crown's breaches of the Treaty, and the price the Government's had to pay with its iwi settlements.
Mrs Turia says she is astounded the option to pledge an oath to the Treaty was dismissed in Parliament as it is contrary to the alliance Maori were meant to have with the Crown.
Last year Mana Party leader, Hone Harawira, was thrown out of the House for trying to pledge his allegiance to the Treaty instead of the Queen, and had to go back and redo his oath according to Parliament's protocol.
The Maori Party has been trying to change the law covering statutory oaths and declarations for six years.
The last change to the oath occurred in 2004 to allow MPs the option of making their pledge in Maori or English.