UNIONISTS have been left furious after one of Nicola Sturgeon’s top civil servants was caught on video telling colleagues his job is about “breaking up” the UK.

Ken Thomson, who serves as director-general of strategy and external affairs, is one of the most senior civil servants in the Scottish Government.

At an internal government event earlier this month, dubbed “mastering the civil service craft”, he said: “I’ll tell you a secret about why I’ve got ‘strategy’ in my job description.

“It’s a word that gets me through some doors in Whitehall, and then they discover that what I’m actually there to talk about is breaking up the Kingdom.”

READ MORE: Unionists 'know they'll lose next referendum', says Lorna Slater

Thomson added, “so it’s a shorthand for constitutional change", in a leaked video seen by the Daily Record. 

The remark has sparked fury from opposition MSPs, who have said it raised questions about using civil servants to boost the case for Scottish independence.

This comes in the same week that Alister Jack revealed the UK Civil Service will look into whether Scottish officials should still be allowed to work on indyref2 preparation. 

But a Tory minister has previously suggested the Scottish Government can legally spend money on whatever it wants. 

Scottish Lib Dem leader Alex Cole-Hamilton said: “Thomson should reflect on whether his comments represent the high standards of the civil service and whether it was appropriate to say this in front of more junior staff”.

He claimed it “speaks to a culture” which stemmed from SNP ministers who are “finding ever more inventive ways to spend money and time on their bid to break up the UK”.

Pamela Nash, chief executive of Scotland in Union, said: “It is not the job of civil servants, who we all pay for, to agitate the break-up of the UK.

“Hearing what was said will confirm many of the suspicions people have about the conduct of this SNP government.

“It’s no wonder the Scottish Government is failing so badly in so many areas when these are the priorities being pursued by its most senior representatives.

“Nicola Sturgeon should condemn this behaviour and offer assurances that this toxic agenda will not infect other areas of the civil service.”

Former SNP councillor Mhairi Hunter hit out at the reaction. Writing on Twitter, she said: "What a load of absolute nonsense. Opposition MSPs whipping themselves up into a frenzy of outrage at someone making a pretty anodyne quip.

"They act like they want to make supporting independence illegal. Can't win the argument so just ban the debate."

Elsewhere, Labour MSP Sarah Boyack said there are “serious questions to answer” on the remark and accused the SNP of having a “constitutional obsession”.

A Scottish Government spokesperson said: “During an hour long Q&A session with Scottish Government staff on November 17, the director general for strategy and external affairs made an informal comment in response to a question about his job-title.

“As outlined during that session, the role of civil servants is to support ministers in a way consistent with the Civil Service Code, good government, organisational values and the democratic process.”