The jury in the Sheridan perjury trial has been played a video in which a man refers to making the biggest mistake of his life.
Colin Fox, a former SSP MSP, identified the man as Tommy Sheridan and in his evidence he accused Mr Sheridan of asking him to say an incriminating party minute was false - which he refused to do.
The trial was played video footage in the days after an emergency meeting of the SSP executive about the revelations in the News of the World.
In the video shown to the jury, Mr Sheridan was allegedly talking about going into the meeting and addressing its membership.
The video was obtained by the News of the World following Mr Sheridan's successful libel action against the newspaper.
Mr Sheridan was identified in the video by Mr Fox, his friend of 30 years.
Mr Fox said he was "disappointed" by the emergence of the video and that Mr McNeilage, who was best man at Mr Sheridan's wedding, had filmed it.
A man's voice in the video can be heard to say: "They want me to come to a meeting that night to explain myself and this is where I make the big mistake. I then make the biggest mistake of my life by confessing."
Mr Fox told the court: "That executive committee of November 9, 2004 was the SSP's 9/11. It was when our totem came crashing down. We would remember that meeting for the rest of our lives."
As well as visiting the swingers' club, Mr Sheridan had an affair with a member of the SSP, Katrine Trolle, the court was told.
Duncan Rowan, the former regional organiser of the SSP for the north-east of Scotland, then told the court he had informed the News of the World about the affair to try to protect another woman, Fiona McGuire, who the newspaper thought was having an affair with Mr Sheridan.
The 37-year-old, who resigned from the party and left Scotland after going to the newspaper, said Ms McGuire had tried to kill herself after she was approached by the newspaper in connection with allegations of a "four in a bed" orgy with Mr Sheridan.
He said he went to the newspaper the day after the emergency meeting because he blamed himself for the "fragile" woman's suicide attempt and had been told by Ms Trolle that she had been having an affair with Mr Sheridan.
He said: "I had to do something to recover the situation. It was because Katrine had said to me on previous occasions that she was having an affair with Tommy Sheridan.
"I believed they had the wrong person, I believed I knew who the right person in the story was."
Mr Rowan said he was wracked with guilt after the article was published and told the court he had left Scotland because he "wanted to get away from the mess".
Mr Sheridan stared straight ahead of him while the evidence against him was given to the court, while Mrs Sheridan sat close by him.
The video above features a shot of an Edinburgh cafe on the site of a meeting involving Tommy Sheridan. It now operates under a new name and different management from that time.