James Shaw's refusal to work with National is being labelled a bad move.
The leader of the Greens is copping criticism for ruling out a coalition deal with National.
Shaw has ruled out forming a government with the Nats, saying it would be unacceptable to his voters.
Business negotiator Troy Bowker told Mike Hosking after 20 years in Parliament, but none in Government, the Greens should've kept more options on the table.
"The Greens ironically could have had a strong position, the ranking [now] in terms of strength in this negotiation in terms of strength is Winston, The Nats (sic), Labour and the Greens last.
Bowker said James Shaw could've been in a powerful position, had he not ruled out working with National but instead has handed New Zealand First more bargaining power.
"James Shaw has immediately put himself into a three way negotiation as the weakest party that wasn't smart."