Cameron's top spin doctor may be called as witness at Sheridan trial

The Prime Minister's top spin doctor could be called to give evidence at the Tommy Sheridan perjury trial after his name was included on a new list of witnesses.

• Spin doctor Andrew Coulson is on Sheridan's witness list

Andrew Coulson, Downing Street's director of communications, is on a list of people whom Sheridan has indicated he might want to call to the witness box.

Mr Coulson is a former editor of the News of the World, the paper which Sheridan sued successfully four years ago. It was that civil litigation which has led to the current trial, where Sheridan and his wife Gail deny giving perjured evidence on his way to being awarded 200,000 in damages.

The drafting of a new witness list was one of Sheridan's first tasks since deciding to sack his counsel and conduct his own defence. In another early foray into his new forensic role, he tried to leave the dock to conduct a cross-examination, but was quickly informed by the judge that he should remain in his accustomed position.

Evidence at the High Court in Glasgow, on the seventh day of the trial, centred on a claim by a former political colleague that Sheridan had confessed to attending a sex club when he addressed the Scottish Socialist Party's hierarchy.

Joanna Harvie, 33, told the jury there was no doubt in her mind about what Mr Sheridan had said. Questioned by Sheridan, Ms Harvie rejected a suggestion that she had not cared about a party member going to the News of the World about Sheridan because it was to "do him in".

The court has heard that the News of the World made lurid allegations about an unnamed MSP in 2004, and that an emergency meeting of the SSP's executive was convened to discuss the article.

Ms Harvie, a journalist who edited the party's newspaper, the Scottish Socialist Voice, and now works on a newspaper for refugees in Glasgow, said Mr Sheridan was "an incredibly high-profile figure" and someone with "an immense reputation." It was the first time an emergency meeting had been called. Before attending, she had spoken to Alan McCombes, another senior figure in the SSP.

"Alan explained the story about an unnamed MSP referred to Tommy. I was hugely concerned. (At the meeting] Tommy explained that the unnamed MSP was him. He said he had attended a sex club on two separate occasions. He said he was sorry for it. He said he did not know what it was that made him do it ... said it was reckless behaviour," Ms Harvie told the court.

"He did not believe the News of the World could prove it was him and if they did name him, he would sue them. Even though Alan had explained to me the day before what the meeting was going to be about, I think I was still shocked all over again to hear Tommy explain it.I was very, very upset."

The advocate-depute, Alex Prentice, QC, asked if there was any doubt in her mind that she had heard Sheridan say those things. Ms Harvie replied: "None whatsoever."

Earlier this week, Sheridan sacked his QC and junior counsel, and Lord Bracadale announced to the jury that he would be conducting his own defence.

The trial continues.