THE horse-trading over the Scottish budget is set to continue after the Greens and SNP last night failed to strike a deal on tax and spending plans for 2018-19.

It means MSPs will vote today on the general principles of the Budget Bill with key details unconfirmed.

The SNP has proposed overhauling the income tax regime north of the border, with new 19p and 21p bands and higher bills for those earning over £33,000.

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At this point in the budget cycle last year, the Greens had agreed to support the SNP’s plan in return for a further £220m of extra spending, most of it for local government.

It was a deal many Green activists thought was too hasty.

In line with Green demands, the SNP has already agreed in principle to amend the Budget to protect council services, increase public sector pay and invest in low-carbon infrastructure”

However talks between Finance Secretary Derek Mackay and Green finance spokesman Patrick Harvie at Holyrood yesterday failed to reach agreement on the details.

The SNP do not need active Green support to win today’s vote, as an abstention will suffice.

However Mr Mackay will not want to risk outright Green opposition in the final vote in mid-February, as that would topple the government, meaning more concessions are likely.

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The Scottish Government has effectively ruled out talks with Labour and the Tories, while negotiations with the Liberal Democrats have foundered over funding for ferry routes.

Hinting at further tax rises as the way out the impasse, Mr Harvie said: “While the discussions have been constructive and professional, it’s clear that there must be significant amendments to the budget as it stands.

“We urge the Finance Secretary to take our proposals forward.

“if he decides not to accept the changes we have proposed, it’s unclear where else he will be able to seek support for his budget."

Mr Mackay said the budget would deliver "investment in our public services, increased support for our economy and fairness for taxpayers".

He said: “I call on parliament to support this budget in order to give stimulus, sustainability and stability to our economy and public services.”

Scottish Tory leader Ruth Davidson warned income tax hikes could deter employers from locating in Scotland if it meant paying a “Scottish surcharge” on behalf of their staff.

She said: “I remain deeply concerned about the trajectory we are taking as a nation.

“The Scottish Government needs to be watchful that we don’t put off investment thanks to our tax policy which, in the end, will only reduce the total tax take, cutting the amount of money we have available for our vital public services. Better in our view to focus on increasing the tax take, with policies focused on growing the economy.”

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Scottish Labour finance spokesman James Kelly urged MSPs to back a “radical alternative” to the SNP’s plans.

He said: “It’s not good enough to tinker around the edges with as many as 260,000 children living in poverty. We should be looking at a budget that stops the cuts to lifeline services and increases Child Benefit.

“Today we will force a vote asking parliament to recognise that the SNP’s proposed tax rates do not go far enough.

“A penny on the top rate doesn’t cut it when the top 1 per cent own more than the bottom 50 per cent put together. We need a radical budget for real change, not more tinkering.”