Nicola Sturgeon’s arrest is a reminder that it’s scandal and standards that bring down parties, not policy

It is remarkable that questions of conduct can damage the SNP in the polls, when for so long abject failures of policy have bounced off Ms Sturgeon’s Teflon popularity, writes Charlie Mowbray

Casual observers, which frankly means most people, regarded Nicola Sturgeon as a decent and principled woman (Reuters)

Nicola Sturgeon, like Boris Johnson, is a leader bringing down her party after resigning.

In the former first minister’s case, she insisted her departure was down to being tired out by the job, having put in a nine-year stint, and it had nothing to do with any upcoming legal cases. The arrests of Peter Murrell, her husband and former SNP chief executive, and the party’s treasure MSP Colin Beattie shortly afterwards were just coincidences.

Now Sturgeon has been arrested herself, spending seven hours in the company of Scottish police before being released without charge. She has vehemently denied any wrongdoing, tweeting a statement written on her iPhone notes like a cancelled musician, in which she stressed it was “beyond doubt” she was innocent, adding her arrest was a “shock and deeply distressing”.