The Liberal Democrat leader Tim Farron has described Scottish people as "trailblazers" of personal abuse in politics during a trip to Edinburgh.
Farron said voters in Scotland led the way with the kind of "heated language" that has dominated UK politics since the EU referendum, and the idea that people on the other side of the debate were "morally worse".
The Lib Dem leader also told BuzzFeed News that Nicola Sturgeon was "undermining" the UK's hopes of staying in the EU, and that Ruth Davidson was a weak leader, as well as Scotland's "voice of Brexit".
Farron, who was in Edinburgh to campaign with the local Lib Dem candidate for May's council elections, told journalists that the SNP's "identity politics" introduced new language into political debate.
"You see in Scotland, in particular – perhaps you were trailblazers in a way for the rest of the country – a kind of movement and a direction of heated and personal abuse that you see," said Farron.
"There’s a danger of, and I’ll be careful with what I say here, 'small n' nationalism or any kind of identity politics where people believe those on the other side are somehow morally different or worse from them.
"I sit alongside the SNP MPs in Westminster and I go out of my way to try to build decent relationships with people on all different parties, and I get on on a personal level with them fine – I think that’s how it should be."
A Lib Dem spokesperson later clarified: “Mr Farron was speaking within the context of the SNP in Scotland with particular reference to the independence referendum of 2014 was a trailblazer for the rest of the country to the abuse that we see online today."
Farron was in the Stockbridge area of Edinburgh inside the constituency of Davidson, and he said the Scottish Tory leader faces a "big problem" in the wake of the Brexit referendum where 75% of locals voted Remain.
He accused Davidson of being a "weak" leader by accepting Theresa May's plans for a hard Brexit, and for failing to speak out against the so-called tax credit "rape clause" which was introduced last week.
"Ruth Davidson has a big problem as a person who, unlike Theresa May, pulled a shift for Remain during the campaign, for which I have admiration for her," Farron told BuzzFeed News.
"But the problem is she is now the voice of Brexit in Scotland while representing one of the most diverse and cosmopolitan areas of the whole United Kingdom, never mind Scotland.
"The Tory revival, if you like, from being absolutely dead in Scotland, will have a real glass ceiling to it if they continue to back Theresa May’s hard Brexit."
Farron added that Davidson's silence on the "rape clause", which forces women who have become pregnant as a result of rape to prove it in order to receive child tax credits, showed she's controlled by Westminster.
"I’m disappointed in Ruth," said Farron. "The problem is it’s one or the other; either she is not the decent person I suspected she might be or she’s really quite weak and [the Scottish party] is being run by a Conservative government from Westminster, and they take no notice of Ruth Davidson.
"She needs to stand up to Theresa May and if she believes Theresa May is wrong she needs to say so, and if she can’t persuade her quietly then she must object noisily."
Farron had further criticism for first minister Nicola Sturgeon, who he accused of attempting to "undermine" efforts for the UK to stay inside the EU for the sake of furthering her "obsession" with independence.
The Lib Dems have proposed another referendum on the deal which is struck between the UK government and the rest of the EU as a result of Brexit negotiations, aiming to give the public a chance to choose their "destination".
"It’s very clear to me the SNP were delighted by the outcome of the EU referendum because it gave them another go at the thing they’re most obsessed about and I don’t think we should do anything to encourage that," said Farron.
"The key thing of this is that, at the moment, the UK is leaving the EU. That is dangerous and the people who think that is a bad thing – and we assume Nicola Sturgeon still thinks it’s a bad thing – need to get beside us and back the call for a referendum on the deal.
"That’s the only plausible way of Britain, including Scotland, staying in the EU."