This time last week, Kezia Dugdale was looking forward to several weeks of berating the SNP leader, Nicola Sturgeon, for hypocrisy over her abandonment, for the time being, of the 50p rate of tax. But it was not to be. Labour's unerring ability to shoot itself in the foot at election time struck again.

Dugdale announced that she was going to scrap the £100 rebate for those earning under £20,000 which had accompanied her proposal to increase the basic rate by one penny. She said that it was no longer required since the Chancellor had increased tax thresholds in the budget and therefore the low paid would not lose out.

She's quite right of course - they won't be paying any more tax than they are now. But they will be paying more than comparable families in England for whom the rise in thresholds amounts to a tax cut. This lent substance to the SNP's claim that Labour was loading tax on people on low incomes. Indeed, she was actually taxing them more than a Tory chancellor.

This was a serious presentational error on the eve of an election. The cost for low income families of one pence on the basic rate was never going to be very great. But it became a central focus of debate in a week in which Nicola Sturgeon had been on the back foot for the first time in years.

The £100 rebate, supposedly paid retrospectively by local councils to compensate lower income families for the increase in the basic rate, always sounded over-complicated. Dugdale said that council leaders had assured her that it was feasible, but it was never clear how much it would cost to administer. However, dumping the rebate without warning only weeks before the election made it look as if Labour were all over the place.

There had already been questions about Labour's seriousness in raising the penny for Scotland, which they vigorously opposed when the SNP proposed a similar measure in 1999. Many believed Kezia Dugdale only proposed it because she had no chance of winning the May election. However, she is right that Scots – including basic rate payers - repeatedly tell opinion polls that they would accept increases in tax if it meant better services.

Cuts in services hit the lower paid hardest. Paying a little over a pound extra a week would be money well spent even for families on low incomes of sixteen thousand if it meant better eduction for their children, better social care and liberation from measures like the bedroom tax. Most would be happy to pay so long as they knew that those on higher incomes were also paying their fair, much larger, share.

But our entire approach to this has been so conditioned by thirty years of anti-tax propaganda that many, especially in the middle classes, regard income tax almost as legalised theft. Indeed, it is only when this argument is turned on its head that you realise how much the prejudice against tax is ingrained in our political culture.

Which brings us to the moment of the week on Tuesday when Nicola Sturgeon challenged the Tory leader Ruth Davidson during the STV debate over how much her party's “taxes”, like tuition fees and prescription charges, would cost. Davidson was so taken aback by this question that she forgot to evade it. She admitted that Tory plans for universities would cost £6000 and prescription charges would be “around £8”. The First Minister had reframed the question and presented free tuition fees as a tax foregone rather than “free stuff”.

So full marks to the First Minister for focussing attention on the “social wage” and the benefits that Scottish taxpayers receive. Mind you it does rather undermine her other claim that introducing a 50p top rate of income tax will inevitably lead to “tax flight” as all those earning over £150,000 a year would scarper across the border. This is based on the rather malign assumption that people on high incomes will do absolutely anything to avoid paying a few pounds more in income tax. But the wealthy also gain from universal benefits like free personal care and free tuition fees, which are worth a lot of cash – more than anything they might lose under the 50p rate.

But the First Minister seems to have largely neutralised the political impact of her top rate tax u-turn thanks to Labour's mistakes and the Tory party's ideological myopia. It was left to the Green Party, the keepers of the spirit of indyref, to stick to their principles and offer a genuinely “Nordic” tax policy

Patrick Harvie's proposal for a 60p tax band, and a rejigging of thresholds to reduce tax on those earning on or below average earnings, most closely resembles the kind of tax regime you find in countries like Denmark. They don't seem to think it is impossible to ask the rich to pay just a little more. Harvie also bit the bullet and promised to scrap the council tax, revalue property, and triple the tax for those in the most expensive houses.

This was based on the report of the cross party commission on local tax reform which condemned the council tax for its manifest unfairness. The commission said that, because home values had not been uprated since 1991, the most expensive homes in Scotland pay only three times as much as the lowest, even though their houses are now worth fifteen times more.

Of course, many will say that the Green Party can indulge in radical fantasies because it will never be in government. But that is not entirely true. Were the Scottish parliament's election system working as it used to, Holyrood governments would usually be coalitions. The Green's would probably be the first choice of the SNP as it was after 2007. So having these proposals on the table is helpful.

But it has been a poor week on the whole for the Scottish parties. They seem to have risen to the challenge of tax devolution by falling flat on their faces. Cynics might say that this is exactly what the Chancellor, George Osborne, and the Treasury wanted to see. The whole purpose of devolving tax powers was to make the Scottish parliament responsible for raising a significant proportion of the money it spends. Hard choices. Economic realism.

The Tories are amused that Nicola Sturgeon seems as unwilling as they are to tax the rich and has used the same argument for not raising the 50p rate that the Chancellor, George Osborne used for cutting it: that it would damage the economy and raise very little in revenue. Similarly, Labour, Greens and the Liberal Democrats have had to propose raising the basic rate of income tax, thus taxing “hard working families” more than the UK Tory government. Ha Ha.

As readers of this column will be aware, the Scottish parliament was only given the power to raise income tax – the “toxic” tax that no UK political party has dared to raise in the last quarter of a century - to damage its radical rhetoric. When George Osborne was searching for a means of filling the hole in his budget caused by the recent slowdown in growth, he didn’t look to raising income tax. Indeed, it is actually illegal to raise income tax in England until 2020 under self-imposed Tory legislation. Osborne looked instead at increasing fuel duties, scrapping higher rate pension tax relief, increasing insurance premium tax – but income tax was never mentioned.

This was the fiscal trap – and the Scottish parties have fallen into it. The question now is can they extricate themselves without ending up as tax clones of the UK parties.