DEREK Mackay has to navigate a thicket of spiky choices when he delivers his draft budget for 2018/19 on Thursday – he is unlikely to emerge unscathed.

Cuts to Westminster revenue funding, a stagnant economy, an ageing population to care for, a business community up in arms over higher income taxes and business rates, and a raft of ambitious manifesto promises to deliver all confront the Finance Secretary.

Whatever he does will anger a good slice of Holyrood and Scotland at large.

A well telegraphed rise in income tax for the better off is likely to grab the headlines, but Thursday is only the start of weeks of horse-trading with opposition parties.

Up to the final parliamentary vote in February, there are likely to be a series of changes and concessions.

The principal opposition parties can be instantly discounted as potential allies in the minority government’s search for consensus.

The Tories abhor income tax bills in Scotland being higher than the rest of the UK.

That means they don’t even back the status quo, far less a more “progressive” system.

Besides, neither Unionists nor Nationalists want to be seen cosying up to each other.

Likewise with Labour.

Richard Leonard is not about to make helping the SNP one of his first acts as Scottish party leader, especially after accusing Nicola Sturgeon of contributing to “Dickensian” levels of deprivation by failing to use Holyrood’s tax powers to raise more for struggling public services.

So with the SNP and Labour as irreconcilable as the SNP and the Tories, that leaves the Greens and LibDems as would-be partners.

Both are problematic.

The Greens have shown themselves ready to back the SNP in the past – for a price -– but have made a £300m pay rise for public sector staff a red line issue this year.

While that may be laudable and overdue, it’s also a tough political sell.

It is tangible pain for intangible gain. People won’t like getting thinner pay packets so others can have fatter ones, especially when it’s not linked to improvements in services.

The LibDem package is superficially more palatable, with tax rises used to pump millions into education.

However Ms Sturgeon has repeatedly declared education her top priority, and agreeing to the LibDem plan would be a tacit admission that it has been under-resourced to date.

Again, politically awkward.

The good news for Mr Mackay is that he doesn’t need the active support of any party.

The tight arithmetic at Holyrood means it only takes another party to abstain to give the SNP government a win.

So if either the LibDems or Greens take a principled huff, that still lets the Finance Secretary secure his budget.

Whether the country appreciates it is another matter.