The Scottish Government has been urged to publish what legal advice it has been given over the holding of a second independence referendum.

Speaking at the Scottish Parliament on Wednesday, Liberal Democrat MSP Mike Rumbles asked the Lord Advocate, James Wolffe QC, if another referendum could be held without the need for a Section 30 order to be granted.

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The order is a technical measure set out under the Scotland Act 1998 and would grant Holyrood temporary powers to hold a referendum that is legally binding and beyond challenge.

The Lord Advocate, however, refused to respond to Mr Rumbles, with the question instead answered by Minister for Parliamentary Business Graeme Dey.

Mr Dey said: "By long-standing convention, the content of any legal advice received by the Government is of course, confidential."

Mr Rumbles responded: "Well what a poor response that was.

"In the spirit of openness and transparency, which this Parliament prides itself on, does the minister not agree with me, just as Scottish ministers demanded the UK Government publish its legal advice on Brexit, and it was published, the Lord Advocate's advice on an independence referendum should indeed be published by Scottish ministers?

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"It would have been helpful if perhaps the Lord Advocate had given us the benefit of his advice."

Mr Dey replied: "I would refer the member to my previous answer but in so doing, point out that the convention I refer to is so long-standing, it goes I believe all the way back to when the Lib Dems were part of the then-coalition executive - quite some time ago of course, which is why perhaps the existence of the convention has left Mr Rumbles' memory."

Scottish Conservative MSP Adam Tomkins joined the calls from Mr Rumbles and asked: "Is it the Scottish Government's view that this Parliament could lawfully pass legislation authorising an independence referendum without a Section 30 order or not - Yes or no?"

Mr Dey responded: "Presiding Officer, I have to refer the member to my earlier answer."

At the conclusion of portfolio questions, Mr Rumbles raised a point of order to question the role of the law officers, the Lord Advocate and the Solicitor General under the Scotland Act.

He said: "The law officers are privileged to be the only two unelected people allowed to sit in this chamber.

"This was written into the Scotland Act so that they are here specifically to give their opinions and views directly to MSPs.

"In my question, I asked what the Lord Advocate's position is on the Scottish Government's competency to organise another referendum on Scottish independence without another Section 30 order.

"I didn't ask what his advice was to the Scottish Government. I specifically asked for his advice to MSPs here in this Chamber.

"Under the Scotland Act, they are here for that purpose. And what I find particularly annoying is that the Lord Advocate is actually present and has taken the decison not to answer my question.

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"I'd like to know from the chair - is it appropriate for the Lord Advocate to sit in this Parliament, in the privileged position he is in under the Scotland Act, and not address MSPs directly, as was the purpose of the Scotland Act in the first place?"

Presiding Officer Christine Grahame responded: "As set out in rule 13.7 of the standing orders, with a few exceptions which don't apply in this instance, oral questions may be answered by any member of the Scottish Government or a junior Scottish minister.

"As the member is aware, oral questions are addressed to the Scottish Government, as your one was, and it is for the Scottish Government to decide who attends to answer each question".