A senior independence campaigner claimed the SNP is a "stain on Scotland’s democracy".

Robin McAlpine, director of the Common Weal think tank and a prominent campaigner for Scottish independence, said the SNP is 'utterly corrupt and has been for years' in a blog post on Thursday.

In a lengthy post entitled 'The foundations of Scotland’s democracy have crumbled and you should worry', he lays bare his thoughts on Scotland's political system, touching on the Cabinet Government, the Scottish Conservatives and the SNP.

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The 48-year-old said he thought it was "finally possible" to write what "everyone has been saying in private" with regards to the SNP, and claimed it is "toxic and nasty".

He wrote: "HQ routinely (and remarkably openly) smears internal critics. It rigs things to favour preferred candidates.

"It simply ignores serious complaints if they’re about ‘the wrong person’. It is toxic and nasty, but people have believed they have no option but to stomach it.

The Herald:

"The real truth is that it doesn’t pretend to act for the party as a whole, but only for the leader and a small clique organised around her. It is a stain on Scotland’s democracy."

The think tank leader also claimed priorities with exam marking lay with how it would make Nicola Sturgeon look.

He wrote: "Let’s take the SQA debacle; like everything else, it seems clear to me that the only real consideration was how the exam problem would make the first minister look.

"She clearly wanted a slight improvement – but not too much. In other words, to look like last year with a slight uptick.

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"It’s plain as the nose on your face that the methodology was retrofitted to achieve the outcome.

"Fearing that the Scottish Government would catch a Daily Mail backlash if poor kids got decent results, it was made sure that they didn’t."

Mr McAlpine then turned his attention to the opposition, stating "Labour is more hobby than party and the Tories are obsessive and irrelevant."

He added: "Every time Sturgeon fails (which is a lot), they manage to fail worse. What’s a democracy without an opposition?"

In response for a request for comment, an SNP spokesman branded Mr McAlpine's claims as “crazed nonsense”.