John McTernan: The price of backing or opposing the SNP's budget will be paid at the ballot box next May

THE Scottish budget has been the vehicle of some of the SNP's greatest triumphs as a government. Overall, John Swinney has proved to be a tough and reforming finance minister – one who has had the personal authority to impose his strategy on his colleagues.

He might not welcome the observation, but with his fiscal conservatism he could slot with ease into the current UK coalition's or the previous administration's Treasury teams. Driving down the costs of government and an associated scepticism about the notion that more government money is the cure for all ills has been the hallmark of the good "Mr" Swinney.

But there's his mirror image, the reckless, populist "Dr" Swinney – the one who appears to think that everything government provides can (and should) be free – whether university education, prescriptions or road bridges. It's this character who was on show on Wednesday when he presented the draft budget to the Scottish Parliament. Politics is a funny old trade, but it's quite something to propose a budget that contains the promise of more than 1 billion worth of cuts that won't be announced until after the budget year commences. How, precisely, are affected services meant to manage the spending reductions? Of course, to some extent it's a game – similar to the refusal to make cuts in the summer in line with George Osborne's emergency budget. There's an implied political message – we don't want to make the cuts, if only we had more freedom (more powers) we could avoid hard choices.

And there is also an implicit political choice. Opposition parties are being asked to collude. This will be tempting to the Scottish Tories and the Scottish Liberal Democrats. They fear that next May they will reap the whirlwind of the Comprehensive Spending Review, so the temptation to hug close to the Scottish Government may well be overwhelming. For Labour a different trap is being set. Just as Mr Osborne hopes to persuade the public that the cuts are Labour's fault, so too do the SNP. Mr Swinney anticipates that Labour's Iain Gray will be unable to support his budget – then the finance secretary will spring his trap: "Where", he will demand, "should the axe fall then?"

This is the choice: collude and support the SNP; or, condemn and alienate the voters. This is high-wire stuff – whoever gets it wrong will be caned next year. So the big question is where do the public stand. Do they want to be misled, or do they value straight-talking? The beauty is that this question can't be focus grouped – the public are notoriously slippery and contradictory about tax and spend. The right answer is a question of judgment for Annabel, Tavish and Iain.

The prize for getting in tune with the public is huge. The punishment for getting it wrong, equally large. The debate will rage until the election next year – and then it will be resolved, whoever is right will win, whoever's wrong will lose.

What price traditional Scottish prudence?