The Scottish Green Party has ruled out entering any electoral pacts with the SNP, citing climate concerns.
A motion on the issue was passed by delegates at the final day of the Greens' autumn conference in Inverness.
Ahead of the party's spring conference, then co-convener Maggie Chapman told The Herald On Sunday newspaper a pact with the SNP was "certainly possible".
She said her party would need to enter negotiations with a clear idea of what they would and would not concede, adding: "It is not something I would ever want us to rule out."
Closing the party's autumn conference, lead candidate for the Highlands and Islands Ariane Burgess criticised the SNP conference, which began in Aberdeen on Sunday, for having events sponsored by BP and Heathrow and accused them of "selling out" to oil companies.
She said: "Only the Greens have what it takes to deliver the transformative change that is needed in the face of the climate emergency.
"And if you want any proof, just look at SNP conference that is opening today. Brought to you by Heathrow Airport and BP, one of the biggest polluters in the world ever.
"Yet more proof that the SNP's rhetoric and eye-catching but distant targets are window-dressing, serving only to stave off criticism.
"For all their talk of change, they are the party of the status quo."
Earlier, Green delegates voted to put climate issues at the heart of any negotiations over the Scottish Government Budget, with a motion calling for turning the "rhetoric of a 'climate emergency' into a reality" by moving to a low carbon economy being passed at conference.
In recent years, the minority SNP administration has relied on support from the Greens to pass its tax and spending plans at Holyrood, with the car park tax among this year's concessions.
"The Greens have shown that we can use the budget negotiations to get things done," co-leader Patrick Harvie said.
The next budget "must recognise the urgency of the climate emergency", he added.