Politics is often as much about sentiments as substance. Few political forces understand this better than the Scottish National party. It has successfully portrayed the Scottish Labour party as the establishment, even though the SNP booted Labour out of power in 2007. It has cultivated an image of being firmly on the left and opposing cuts even though – with the commendable exception of limited land reform – it has thus far failed to redistribute wealth and power. The independence referendum politicised Scotland, and the SNP has harnessed that energy: the party is exciting and inspires its supporters. Its fired-up grassroots base passionately defends its record from all criticism, including, undoubtedly, this one.

Scottish Labour is today launching an audacious attempt to call the SNP’s bluff. Scotland has the ability to raise income tax. But the SNP had a persuasive argument against using this power: until 2017, any increase in income tax has to be across the board, meaning that low-paid workers would be hit, too. That enables the SNP to maintain its cross-class coalition with a series of nods and winks: well-off Scots know they will pay whatever George Osborne wants them to, while the SNP can protest to others that its hands are tied. It can launch passionate broadsides against Osborne’s austerity, while bemoaning its inability to do much about it – without escaping the UK, of course.

But Labour has found a way around it. The party would indeed hike income tax by 1p, which would be across the board. But it would compensate Scots earning a pay cheque of less than £20,000 a year with a £100 rebate delivered by local authorities. By the party’s calculations, a Scot earning the living wage would have an extra £51 in their pocket; while – it points out cheekily – the first minister, on a salary of £144,687, would have to fork out an additional £1,447 a year. That would leave the Scottish government with an extra near half a billion pounds. Suddenly cuts don’t become an imposition of a Westminster Conservative government that Scots did not elect. Instead, they become a choice.

In the SNP’s Scotland, colleges have been battered with cuts to jobs and courses, while student numbers have plummeted. An eight-year council tax freeze has meant two things: cuts to local services, as well as the Scottish government splashing around money to compensate that could be better used elsewhere. Scottish Labour is saying: we can raise the money to avoid cuts now being proposed by the SNP.

Let’s not be under any illusions here. Scottish Labour faced a real battering in the general election, and little it does now will turn that around. A toxic image of the party is embedded in the consciousness of many Scots, and often particularly those who used to vote for it. A fateful decision to ally with the Conservatives for Better Together, rather than launching its own separate and positive campaign, helped crystallise grievances accumulated over many years. A recent report found that Scots believed Labour were “an incompetent version of the Tories”.

There is no more impressive politician than Nicola Sturgeon in the British Isles, and the SNP can count on the loyalty of many voters who oppose, say, cuts or nuclear weapons and so on. But as a longer-term strategy, Labour can begin to puncture the SNP’s image. It can highlight that the SNP is an unwieldy, contradictory coalition, and try to unpick it. Yes, this can only be one part of a far-reaching process of Labour rebuilding its own shattered image, of offering contrition to the Scottish people for its mistakes. But wrestling the SNP for the torch of social justice is surely Scottish Labour’s only path to political salvation.