The SNP could avoid a budget collapse with a bail out from its pro-independence partners at Holyrood.
Finance Secretary Derek Mackay has been trying to drum up opposition support for his minority administration’s controversial tax and spending plans.
Greens co-convener Patrick Harvie said he was “not willing” to see the Budget fall, although sources in both negotiating teams stressed a deal had yet to be done.
Speaking yesterday, Mr Harvie said: “If parties just dug their feet in and said ‘my way or the highway’ then the whole thing would fall and we would begin to see emergency cuts being made to public services across Scotland.
“I’m not willing to see that happen.”
Mr Mackay needs the support – or abstention – of one other political party to secure the parliamentary majority required.
The six Green MSPs are seen as crucial to the minority government’s Budget passing its first parliamentary hurdle tonight but they have demanded commitments to increase income tax and stop council cuts.
Scottish Government sources close to the talks were last night unwilling to rule out changes to the tax system.
Finance Secretary Mr Mackay held talks on Wednesday afternoon with Scottish Liberal Democrat leader Willie Rennie, whose demands for a £400million boost to services fell on deaf ears.
Scottish Conservative MSP Murdo Fraser urged Mr Mackay to snub opposition parties who are calling for him to raise taxes and instead cut the amount of money leaving people’s paypackets.
He said: “We will talk constructively with the Scottish Government about its budget plans – so long as it abandons its bid to make Scotland the highest-taxed part of the UK.
“Derek Mackay needs someone on board to ensure this vital process goes through.
“It’s the most significant budget in Scottish Parliament history, and we don’t believe he should side with other opposition parties in hiking taxes for workers and businesses.”
Kezia Dugdale, the Scottish Labour leader, said the SNP’s approach to council funding mean her MSPs could not support the Budget.
She said: “Labour will not vote for any SNP budget that cuts £327million from local services like schools and care of the elderly.”