NICOLA Sturgeon has defended herself against criticism over her social media links with abusive so-called cybernats.

It emerged the First Minister has met and follows on Twitter a troll called Robert Dickson, who has heaped vile abuse on a string of politicians.

She follows another cyberbully called Ian Barr and an abusive Twitter account which has the name YESThatcherDead.

The revelations sparked fresh calls for Ms Sturgeon to distance herself from the cybernats and to denounce their online abuse and bullying.

But her official spokesman said: "The First Minister follows almost 3500 people on Twitter.

"Whenever she is aware of unacceptable online behaviour, she has repeatedly condemned it, from whichever side it comes.

"As anyone who uses Twitter knows, it is not possible to keep up with every comment that appears on such a large news feed."

Mr Dickson has used social media network Twitter to issue foul-mouthed attacks on a number of political figures including Labour's Kezia Dugdale and Margaret Curran, and the Lib Dems' Jo Swinson.

Tweeting under the name Roy1Batty, he said of former Tory employment minister Esther McVey: "I have never used this epithet towards a woman... but Esther McVey is a ****. Pure and simple...a ****. Sorry."

He also threatened physical violence against former Scottish Labour leader Jim Murphy, tweeting: "Ten minutes in a locked room with Murphy...that's all I ask."

The First Minister tweeted Mr Dickson last year to say it was "lovely" to have met him and his son after he apparently introduced himself in person.

Mr Barr used Twitter to abuse Alistair Darling, sending the message: "Shut it you f****** ****. You're no Scotsman."

The First Minister has 228,000 followers on Twitter, which allows users to send brief messages of up to 140 characters.

She has been praised for running her own Twitter account, unlike some leading politicians, and engaging widely with followers.

A Scottish Labour spokesman said:

"There is absolutely no room for this kind of vile abuse in Scottish public debate.

"No matter how much we may disagree with someone's political, there is an obligation on all of us to act with respect and courtesy.

"It's about time Nicola Sturgeon got a grip on her nationalist supporters.

"Telling them off after the fact just isn't good enough.

"Until the leadership of the SNP properly confront their supporters this kind of vile abuse will carry on."

Alex Johnstone, the Scottish Conservative MSP, said it was "shocking" the First Minister had engaged with an online troll.

He said: "So-called cybernats are a particularly nasty breed of people.

"SNP politicians should be very careful about the company they keep, it could come back to haunt them."

It emerged the late Charles Kennedy was subjected to vicious online abuse by cybernats in the weeks before his death.