A man accused of sending threatening messages to First Minister Nicola Sturgeon on social media and of abducting a sheriff should be barred from representing himself in legal proceedings, a court has heard.

William Curtis and another man with whom he is accused of the incident involving the sheriff both previously said they do not want legal representation and maintained that position when they appeared at the High Court in Edinburgh on Wednesday.

However, Advocate Depute Chris McKenna said it would not be appropriate for the men to represent themselves due to the involvement of two vulnerable witnesses in the case.

He said it would not be suitable for the men to cross-examine vulnerable witnesses and asked the court to prohibit them from conducting their defence, and for lawyers to be appointed for them.

Mr McKenna said: “It’s the Crown submission that it would be manifestly inappropriate for either accused to be given the opportunity to cross-examine either of these witnesses.”

He said that while the vulnerable witnesses do not relate to the sole charge involving Philip Mitchell, there would be nothing to stop him from questioning them.

He told the judge Lord Weir: “It is a balancing act between the fairness we must give to the accused and the best interests of the vulnerable witnesses.”

He added: “It cannot be said that the court appointment of legally-qualified representatives would risk prejudicing justice, far from it.”

Curtis, 69, is accused of behaving in a threatening or abusive manner which was “likely to cause a reasonable person to suffer fear or alarm” by sending emails and posting messages on social media in which he made threatening remarks towards Ms Sturgeon on various occasions between February 27 and March 6, 2019.

He is further accused of allegedly sending or causing a message to be sent through social media on March 9, 2019 to Stewart Stevenson MSP which threatened him and contained a link to a video relating to the murder of the MP Jo Cox.

He also faces two other charges of posting messages of a “threatening and abusive nature” on social media in October 2020 and June 2021.

Curtis and Philip Mitchell, 60, are accused of assaulting and abducting a sheriff in a car park in Banff, Aberdeenshire, on June 29, 2021.

It is alleged they seized Robert McDonald, sheriff of Grampian, Highlands and Islands, at Banff, pulled him to the ground, sat on top of him and detained him there against his will.

All the alleged offences happened in Aberdeenshire.

Curtis has pleaded not guilty to the charges while Mitchell has not yet entered a plea.

At the hearing in Edinburgh on Wednesday, Curtis said he would continue to represent himself.

He said: “There’s not a barrister in the country would touch me because they are not good enough. I will continue to defend myself.”

Lord Weir said he would consider the matter of legal representation before issuing a written decision.

He adjourned the case until September 8.