NICOLA Sturgeon has backed Environment Secretary Roseanna Cunningham after her public “meltdown” when the Westminster terror attack halted a Holyrood debate on independence.

Ms Cunningham refused six times to apologise for her “totally unbecoming” behaviour, when she was caught on camera shouting and pointing at Tory MSPs on Wednesday afternoon.

MSPs had been debating the SNP’s plan to stage a second referendum.

Presiding Officer Ken Macintosh told the chamber he was suspending proceedings because of events at “our sister parliament”, which had been attacked around 80 minutes earlier.

Tory MSPs said Ms Cunningham then complained angrily that it was an “absolute disgrace” the proceedings were being suspended, as it was giving in to terrorists.

More controversially, Tory sources also claimed she said “This is because you don’t want to talk about independence”, although this has been denied by the SNP.

Most of her frustration appeared directed at Tory Murdo Fraser, who had suggested suspending the debate.

One witness said: “She was having a bit of a meltdown. I turned away. Others then heard her say something like 'You are only doing this because we are debating independence'.”

Tory deputy leader Jackson Carlaw called Ms Cunningham’s outburst “absolutely disgraceful” and “totally unbecoming” given her senior position and the gravity of the situation.

The Tories later called on Ms Cunningham to say sorry for her "embarrassing outburst".

In farcical scenes at Holyrood on Thursday, one of Ms Sturgeon’s advisers tried to hide Ms Cunningham from the press after First Minister’s Questions, escorting her down a back stair and through the public lobby in a bid to dodge reporters.

However Ms Cunningham was found by the media regardless, who asked whether she would apologise for her action and whether she said the comment on independence attributed to her.

The Perthshire MSP refused six times to apologise, and did not to deny the independence remark, saying merely “You have the comment”, referring to a statement from the SNP.

Asked later if Ms Sturgeon still had confidence in Ms Cunningham, the First Minister’s official spokesman said: “Yes”.

He denied Ms Cunningham mentioned independence in the way it was attributed to her: “She never expressed any such view."

However he refused to explain the basis for the denial, which contradicts eyewitness accounts.

Tory chief whip John Lamont said: “It’s disappointing to see both the First Minister and Roseanna Cunningham herself fail to condemn this behaviour.

“It was an embarrassing outburst which reflected badly on the Scottish Parliament.

“The best thing this MSP could do would be to face up to what she said and apologise, rather than hiding from it.”

The SNP statement on Ms Cunningham’s action said: "Roseanna’s first thoughts are with all of those affected, and while she did initially take the view – shared by some from other parties – that business should not be suspended in the face of terrorism, she fully supports the decision, given the seriousness of events.”