Mr Sheridan is alleged to have admitted attending a swingers club The Tommy Sheridan perjury trial has heard an ex-colleague compare the former MSP to a Conservative peer who was jailed for lying in court.
Allan Green, 53, told the High Court in Glasgow he was appalled a man known for his honesty would follow the path of Lord Jeffrey Archer.
Mr Sheridan and his wife Gail, both 46, are on trial accused of perjury.
They are accused of lying to help him successfully sue the News of the World in 2006. They deny the charges.
Mr Sheridan won £200,000 in damages after the newspaper printed allegations about his private life, claiming that he was an adulterer who had visited a swingers club.
“He was very effective at getting socialist ideas across in the media”
Allan Green Witness
After a police investigation, Mr and Mrs Sheridan were charged with perjury.
Giving evidence on the third day of Mr Sheridan’s trial, Mr Green said that he first met Mr Sheridan in the mid-1990s as the Scottish Socialist Party (SSP) came into being.
The supply teacher said he was pleased when Mr Sheridan was elected as convener of the party.
He told the court: “Tommy used to be a tremendous ambassador for socialism. He was very effective at getting socialist ideas across in the media.”
Mr Green said he was the SSP’s national secretary when he called a meeting in November 2004 to discuss rumours about Tommy Sheridan’s sex life.
He told the court the former MSP admitted visiting a swingers club but then shocked the gathering saying he would deny it publicly and take legal action to clear his name.
Mr Green said he was appalled a man known for his honesty would follow the path of Conservative Lord Jeffrey Archer, who was famously jailed for perjury.
He insisted that everyone knew what he called “the sordid and sad truth”.
It is alleged that Mr Sheridan made false statements as a witness in his defamation action against the News of the World on 21 July 2006.
He also denies another charge of attempting to persuade a witness to commit perjury shortly before the 23-day legal action got under way.
Mrs Sheridan denies making false statements on 31 July 2006, after being sworn in as a witness in the civil jury trial at the Court of Session in Edinburgh.
The trial, before judge Lord Bracadale, is due to last between two and three months and is expected to become the longest perjury case in Scottish legal history.
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