In eighteen months, three or more Green MPs could become Cabinet ministers for the first time in the party's history.
If the Greens helped the Labour Party get over the line at the general election in 2014, they would push hard for portfolios in a coalition government.
The Green Party is already well-advanced in planning to govern, and will further develop their goals at this weekend's annual conference in Christchurch.
Chapman Tripp solicitor Linda Clark wrote in a think-piece this week that if Labour formed a government with Greens next year, three Green MPs were likely to be part of the Cabinet.
She said that Greens co-leader Russel Norman was likely to become Economic Development Minister, co-leader Metiria Turei would be given a social policy role, and Kevin Hague could get the health portfolio.
Labour Party sources told the Weekend Herald that they agreed with this prediction, in particular the possibility that Mr Hague, a former District Health Board chief, would get the health portfolio in a Labour-Greens government.
They said Mr Hague was "highly competent" and "trustworthy", with one source saying Labour "would rather work with him than any other Green MP".
If Labour leader David Shearer became Prime Minister, it was expected that David Parker would become Finance Minister.
This left the economic development role for Russel Norman, though some suggested he could also take on the energy portfolio.
There was less certainty about what Cabinet position Greens co-leader Metiria Turei could take.
At present, she speaks for the party on social issues, housing and Maori affairs.
Former Green MP Sue Bradford said that Labour would fight tooth and nail to hold the highly significant and big-budget social development portfolio, so Ms Turei could have to settle for the Maori affairs role.
Ms Bradford also noted that Greens would want to have a high-ranking environmental portfolio, and suggested that Ms Turei could become Conservation Minister.
Dr Norman, Ms Turei and Mr Hague were seen as the only "shoo-ins" for a Labour-Greens Cabinet.
But some other Green MPs have also impressed the Labour Party.
Conservation spokeswoman Eugenie Sage and climate change spokesman Kennedy Graham were both considered "safe" Green MPs, but some within Labour doubted whether they had the profile to be Cabinet Ministers.
Immigration and women's issues spokeswoman Jan Logie was seen as hard-working and competent, and could be an outside chance for an associate ministerial role.
However, one source suggested that Ms Logie was not "aligned" with the party leadership, and this could affect her chances of getting an important role.
MPs Catherine Delahunty and Denise Roche were also believed to be in this category.
All three of these MPs were from the hard left of the party, with strong social justice backgrounds.
• Co-leader since 2008
• Possible portfolio: Economic Development, Energy
Metiria Turei MP
• Co-leader since 2009
• Possible portfolio: Associate social development, housing, conservation
• MP since 2008
• Possible portfolio: Health, Associate ACC