A FEW days ago I interviewed John Swinney, the Finance Secretary, for the latest issue of The Herald's regular referendum supplement, Scotland Decides, which comes out next Wednesday.

We talked about the economic case for independence, marathon running and the direction of the campaign.

In the course of our chat, I also asked him about the tone of the debate. Did he believe the process was becoming a little unpleasant? His answer could not have been clearer. "No I don't," he said. "We've got here through absolutely and totally, unreservedly, democratic, civic debate. We are now at a situation where you've got John Kerry saying about the referendum in Ukraine, 'You don't do it that way, you do it they way they are doing it in Scotland'. We've got this open democratic process that's been arrived at by civic movements, civic pressure and I think we've got a lot to be proud of."

Mr Swinney isn't the first senior nationalist to dismiss concerns about the tenor of the referendum campaign and hold it up as a model of democratic debate admired around the world.

After this week, that view looks hopelessly optimistic. In the past few days, Alistair Darling, the leader of the No campaign, has been accused of likening the SNP to Nazis, or at least agreeing with an interviewer who used a phrase associated with Nazi ideology in connection with Scottish nationalism. No sooner had their outraged demands for an apology been met with an indignant denial than the murky world of Twitter woke up (does it ever sleep?) to the two big stories of the week: JK Rowling's £1 million donation to the No campaign and furore over a spin doctor's email to a newspaper concerning Scottish Labour shadow cabinet member and Better Together volunteer Clare Lally.

Both women were subjected to torrents of abuse, much of it completely vile, from the so-called cybernats, those online freedom fighters who lash out at anyone who disagrees with them. In the case of Ms Lally, they objected to her describing herself at a Better Together rally as "just an ordinary mum from Clydebank" without reference to her Labour role. Her party links - hardly secret - were highlighted by a popular and particularly forthright pro-independence website, Wings Over Scotland, and were also the subject of Campbell Gunn's email to a journalist.

There are legitimate and important lines of inquiry here. If Alistair Darling had concurred that the SNP's brand of nationalism was no different from the Nazis', that would be extremely offensive. If Mr Gunn broke the code of conduct governing special advisers' behaviour (a charge robustly rejected by his boss, Alex Salmond) it would be a sacking offence. Neither story, however, paints the referendum process in an inspiring light.

Nor are they the first of their kind. The Lotto-winning Yes campaign donors Colin and Chris Weir have also been subjected to "downright nasty" personal abuse. In recent months cybernats have rounded on business people who have expressed support for a No vote and, last week, US President Barack Obama when he backed a "united" UK. In yesterday's Herald we reported claims by Gavin Hewitt, the former chief executive of the Scotch Whisky Association, that senior SNP figures had attempted to "intimidate" business leaders during the referendum campaign, something the party said it had no knowledge of. At Holyrood, meanwhile, an academic giving evidence on how independence might affect Scotland's diplomatic representation abroad called for an apology after he was shouted down by an MSP who disagreed with his assessment.

If the rosy glow of the referendum process alluded to by Mr Swinney has faded to a glimmer, this week might at least prove a watershed. Former first minister Henry McLeish and Kirk Moderator the Right Rev John Chalmers called for a halt to online attacks after Ms Rowling was targeted. During First Minister's Questions, Mr Salmond condemned the "handful of mindless idiots" who were "polluting" the debate. In a separate move, more than 40 MSPs from across the parties signed a parliamentary motion condemning all personal attacks on those who speak out in the debate. Let's hope such warnings are heeded. The next 95 days could be quite an ordeal for everyone if they are not.