IT’S legally difficult to comment on the guilt or innocence of Michelle Thomson, the SNP MP accused of improper property dealings. But one thing is clear: the reaction from many Labour Party unionists – “the Tartan Tories’ true nature unmasked!” – and from some nationalists – “it’s a treacherous Red Tory conspiracy!” – isn’t impressive. These reactions reflect poorly on Scottish politics so soon after the optimism of the referendum.

Predictably, many left-wing Labourists have been buoyed by this scandal, seeing it as proof of their view that the SNP’s character is pro-business, anti-working class. To them, I offer the old adage that politicians who own 10 houses shouldn’t throw stones. Even if Thomson is found guilty, the case is small fry next to Labour’s long record of promoting greedy and feckless business practices.

There’s Robert Maxwell, the ex-Labour MP and business mogul who swindled £440 million from his company’s pension scheme. There’s ex-Paymaster General and self-declared tycoon Geoffrey Robinson, a key ally of Gordon Brown, who was embroiled in a succession of property and corporate scandals but remains a Labour MP.

There’s Blair ally Stephen Byers, who offered himself as a “cab for hire” (his words) to corporate lobbyists. There’s the allegations surrounding Tessa Jowell’s husband’s £340,000 loan from Blair’s bunga-bunga buddy Silvio Berlusconi. There’s the million pounds Labour took – and returned – from Formula 1’s Bernie Ecclestone, and its (coincidental?) link to a U-turn on tobacco advertising. And then there’s MPs’ expenses…

Even Corbyn’s allies aren’t blameless. Michael Meacher, a rare Corbynite in Labour’s Parliamentary Party, once owned a distinguished property portfolio of 12 houses according to The Guardian. Illegal? No, but perhaps it should be. Meacher himself backed a ban on second homes before his leafy suburban empire came to light.

Let me be clear: I’m not trying to bury Labour’s objections under moral equivalencies.

The point is, cheap shots simply discredit all of politics; everyone can play the game, but nobody wins.

Nonetheless, there are real issues here: political issues. When I examine the brazen rhetoric used by Thomson’s company – openly boasting that “cash is king” and that “it’s possible to turn a profit” by ripping off poor home owners – it raises questions about the SNP’s guiding vision of our movement.

I doubt that any technical rules have actually been broken. But to pretend this case is simply unionist bellyaching is wrong. Our movement must be open and honest enough to admit wrongdoing and reflect on weaknesses.

I hope nobody will consider me disloyal for saying this, because I’m loyal to the cause of independence, not the day-to-day workings of any party’s spin strategy. For me, the scandal doesn’t raise any questions whatsoever about the legitimacy of independence. But it does highlight concerns about the SNP’s overwhelming dominance of the issue.

Put simply, and without wishing to offend anyone, no party is big enough to encompass the radical left and Michelle Thomson.

Leave aside the technical questions, and focus on the politics. Her vision of society’s future is radically different from mine. I back independence because Westminster offers no channels to redistribute wealth and power. Thomson came to independence from a “cash is king” perspective. She’s entitled to defend her values, as I am to defend mine. But can you wedge our conflicting visions into one organisation? I doubt that.

It also raises questions about our strategy. Longer-term, will building an all-powerful party stimulate support for independence, or choke it off?

I’ll reiterate my long-standing view that monolithic, one-party politics could haunt the independence movement if we don’t fix it. At the moment, the SNP is riding high on a wave of acclaim because people have been sickened by Westminster’s corruption and elitism as epitomised by the Better Together alliance. But so much of that acclaim rests on the brilliant performance and irreproachable personality of Nicola Sturgeon.

Let’s remember: Tony Blair became Prime Minister on a similar wave of indignation at the sexual and political hypocrisy of John Major’s Tories. Blair famously told us he was a “pretty straight guy”, and millions believed him.

But “Teflon Tony’s” reputation didn’t last. The drip-drip of allegations about sharp practices in his entourage took their toll, and one disastrous mistake – uncritically siding with George W Bush – undermined him and Labour forever.

Labour paid the price for subordinating a diverse anti-Tory movement to the task of electing an all-powerful government based on a charismatic leader. Even truly incorruptible leaders are vulnerable, because they can’t police the views and behaviour of their allies, as Nicola Sturgeon is discovering. It’s obvious, in retrospect, that New Labour’s monolithic model was a brittle one. Our task is to take that lesson to heart.

As Corbyn will have to discover, diverse multi-party politics is the future. There’s a place for pro-independence businesspeople in parliament, I’m sure. But working class, pro-independence Scotland needs its own voice – and the two can’t be conflated. Political variety and respect for difference keeps us strong; the alternative – one big party with an irreproachable leader – never endures.

We need a real Yes Alliance in Holyrood that respects diversity rather than squashing it into a pre-packaged, one-size-fits-all product.

That’s the politics behind the scandal. Let’s talk seriously about that, rather than point fingers or cry “conspiracy” and “traitor”. Cheap point-scoring trivialises our politics; let’s have a real debate about ideas and the future of Scottish society, now and after independence.