THE Greens could walk away from the Scottish Government’s budget if Derek Mackay continues to “walk away from the evidence” of the climate emergency.

Patrick Harvie has hit out at the SNP finance minister, warning him that striking a budget deal with any other party in Holyrood would be “irresponsible”.

The MSP’s comments came as Mackay hinted over the weekend that he could be prepared to reach an agreement with Labour or the LibDems.

Nicola Sturgeon’s minority government has relied on the support of the Greens to get its budget through Holyrood since 2017, but the two parties have diverged in recent weeks.

Harvie’s party say they want “a transformative shift in public investment away from trunk road expansion and upgrades, and into public transport and cycling and walking infrastructure”. That could include cancelling the duelling of the A9 and A96 and the proposed £120 million Sheriffhall roundabout.

Mackay is due to publish his budget on Thursday.

READ MORE: Scottish Greens call on Government to focus on public transport in Budget

The delay of the Chancellor Sajid Javid’s budget means the Scottish minister doesn’t have much time to get it backed by MSPs.

There is little more than a month for Mackay to agree a budget acceptable to a majority of MSPs.

Last Friday, he promised that the “global climate emergency will be at the heart of the Scottish Budget”.

He said: “We have already put in place the most ambitious climate legislation and targets of any country, including decarbonising Scotland’s railways by 2035 and making the Highlands and Islands the world’s first net zero aviation region by 2040.

“This budget will set out how our spending plans and investments will help us achieve these ambitions.”

Harvie was sceptical. He said: “The Scottish Greens have worked hard over recent years to put constructive pressure on the Government to secure environmental protections, as well as a fairer tax system to help fund council services.

READ MORE: Environmental protection must be a priority for a post-Brexit Scotland

“This year we have been clear that this must be a climate emergency budget, which is why we’re warning today that the Scottish Greens will only support a genuinely transformative response.

“That must mean shifting decisively away from high-carbon spending, as the Government’s own Infrastructure Commission has said. But it also means redirecting serious investment into warm homes and public transport to lower Scotland’s emissions and tackle inequality.”

“Our proposals to Derek Mackay included free bus travel for young people as one positive move that’s well within his power. It would be irresponsible for him to instead choose to keep the status quo,” Harvie added.

“This is a government with form when it comes to failing to meet rhetoric with action, but the climate science shows the coming years will be critical and need decisive action. I hope the Scottish Government doesn’t continue to walk away from the evidence. The Greens remain open to dialogue.”

In his statement on Friday, Mackay said: “The global climate emergency was at the centre of our Programme for Government and will be a priority theme in the budget this week.”

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Mackay urged all MSPs to “work constructively” to pass the budget in “good order”.

There has been fierce opposition to the Greens’s demands from business groups.

Dr Liz Cameron, chief executive of the Scottish Chambers of Commerce, urged ministers “not to compromise our future prosperity” in the name of climate change.

She said: “The last thing business needs right now is for any major U-turns, particularly with our transport infrastructure.”

Stewart Nicol, chief executive of the Inverness Chamber of Commerce, said the road upgrades were necessary to support thousands of potential jobs in Scotland’s “booming” offshore wind sector.