An SNP aide has been asked to apologise after suggesting Conservatives and unionists "embraced" fascism and Nazism.

Ross Colquhoun, a digital strategist for the party, made the comments in a series of tweets on Tuesday evening.

Colquhoun was employed by the SNP after co-founding and organising the pro-Yes cultural campaign group National Collective during the independence referendum.

The tweets were sent in response to an article in which a Conservative MP accused vocal opponents of Donald Trump as "virtue signalling".

The foreign secretary Boris Johnson agreed with the comments.

He tweeted: "Sound familiar? In unionist/Tory world, nobody really opposes all this nasty stuff, it's just 'virtue signalling'. Absolutely bonkers.

"You are the people who are embracing fascism for political gain. You are the people who don't understand why people would oppose fascism.

"The very British values and history that the No campaign promoted in 2014 have been thrown under the bus for Tory electoral gain.

"Britain once proudly fought Nazism and fascism. You now actively embrace it whilst pretending those standing against it are the problem."

In response to Colquhoun's comments, the Scottish Conservatives have called on him to apologise.

A party spokesman told STV News: "Comments like this have no place in modern political discourse, and the SNP need to distance themselves from them.

"All too often we've seen cybernats throw disgusting insults like this at those who hold a different view to them, and they need to learn that it does nothing to help their cause.

"We would now expect Mr Colquhoun apologise for these comments and the offence he has caused."

In a statement to STV News, Colquhoun said: "The tweets reference Tory pandering to an extreme right-wing Ukip agenda, stoking up fears of immigration, lists of foreigners, go home billboards for immigrants - all for electoral advantage."

The SNP distanced themselves from their strategist's comments, describing them as a "personal" view.

A spokesman said: "Mr Colquhoun has been in the US over their election period and his personal comments reflect his previously stated views about the language used during the EU referendum."

During the US presidential election, Republican Donald Trump was supported by a new movement termed the "Alt Right".

The Anti-Defamation League, which monitors extremist and fascist groups in the United States, has warned: "Though not every person who identifies with the Alt Right is a white supremacist, most are and 'white identity' is central to people in this milieu."

At the weekend, attendees at an "Alt Right" conference in Washington DC were filmed giving Nazi salutes after a speaker declared: "Hail Trump! Hail our people! Hail victory!"

Ahead of November 8, the leader of the American Nazi Party said a win by Donald Trump would present "a real opportunity for people like white nationalists".

The North Carolina branch of the Ku Klux Klan will hold a parade early in December to celebrate Trump's victory.