The message, sent to members of the Scottish Greens on Friday, announces the postponement of a vote on the final deal until August 28 and pledges to provide the wording of an agreement to members by August 20.
The New Zealand model, which has seen Green Party MPs in that country take on ministerial portfolios while not being in an official coalition, is being considered by civil servants and Government lawyers, the email said – seeming to confirm one of the group’s eight MSPs will take on ministerial office.
Under the title “important announcement”, the email said: “We need to postpone the question and answer sessions planned for this week, as well as the decision-making EGM (emergency general meeting).
“This is not due to any problem – the Political Co-operation Working Group (PCWG) is very pleased with the progress of the talks so far.
“Both sides are enthusiastic about what’s being developed, and for exactly those reasons we need to take more time to ensure the small-print works for us.
“In particular, the New Zealand model is something which has never been tried in the UK before and the civil servants and Government lawyers need more time to finalise the technical aspects of how it will work in a Scottish Parliament context.
“We can say that both sides are expressly clear that we are not talking about a coalition, but we are looking at a deal which is broad in its scope.”
Plans to discuss the deal at an emergency general meeting on August 14 have also been shelved, according to the email.
Last week, it emerged that a deal could be finalised as early as Friday.
Nicola Sturgeon announced talks had been launched on the creation of a co-operation agreement between the two parties after May’s election, which saw the SNP fall just one seat short of an overall majority.
The idea, according to the First Minister and the Greens, would see co-operation over specific issues, without a formal coalition deal.
Areas of co-operation are likely to include Scottish independence, which both parties support.
Greens co-leader Lorna Slater said in May the deal could allow for long-term budgeting to be done, rather than the usual annual negotiations the SNP are forced to go through to secure budget deals when ruling as a minority administration.