Labour leader Phil Goff says the Maori Party is going against what Maori voters wanted by negotiating with the National Party.
National is finalising support deals with ACT, United Future and the Maori Party after Saturday's decisive election result.
The Maori Party's MPs yesterday headed back to their electorates to conduct 40 hui after a second round of talks with Prime Minister elect John Key at which a draft agreement was concluded.
The deal involves ministerial positions outside cabinet and policy concessions, which included movements on the Maori seats and the foreshore and seabed legislation.
Maori Party leaders Tariana Turia and Pita Sharples have until Sunday to come back to Mr Key and sign up to support his government.
One hui, held by Dr Sharples in south Auckland last night, favoured the deal.
Mr Goff said the Maori Party had decided to "bind" itself to National.
Keeping Stock can understand Goff's frustration, but Labour has been out-manouvered by both John Key and the leadership of the Maori Party, after being spurned by Labour in 2005. Tariana Turia's mana was badly dented by Labour rushing through the Seabed and Foreshore Act, and having Goff diss the Maori Party now will not help. And Goff should also not be too enthusiastic about quoting figures from the election, given that only 55% of registered Maori voters went to the polls last Saturday - the so-called "Maori mandate" for Labour is nowhere near as strong as Phil Goff would have us believe.