Scottish Socialist Party colleagues of Tommy Sheridan were jealous of the publicity he received and thought he ought to be taken down a peg or two, a court heard.
Former party press officer Hugh Kerr, 66, said success in the 2003 election was followed by hate-filled conflict within the group.
He said the unity that members once enjoyed was affected by people who were interested in power and money and by the setting up of a “party within a party” by several women members.
Kerr was giving evidence as the first witness to be called by Sheridan as he defends himself against perjury charges at the High Court in Glasgow on Friday.
He and his wife Gail, both 46, deny lying under oath during the former MSP’s successful defamation action against the News of the World newspaper in 2006.
The case followed the Sunday tabloid’s claims that he visited swingers’ clubs.
Kerr, a former Member of the European Parliament for Labour who later helped launch the SSP, said he decided to leave his party role in March 2004 after members became hostile towards him.
He said: “There were always people who were envious of the amount of publicity you got, and as your press officer they associated me with you.”
The witness added: “There were people who clearly thought that you were well above your station.
“They thought you were too big for your boots and ought to be taken down a peg or two.”
Asked by Sheridan about internal divisions in the party, the witness replied: “The conflicts within the SSP were quite remarkable in their intensity and the hostility they generated.
“People were clearly hostile to you, and because I was seen to be close to you, they were hostile to me as well.
“There was a lot of hate, visceral hate generated in this conflict.”
The trial heard later that the cost of the investigation by Lothian and Borders Police into perjury claims against Sheridan exceeded £1 million.
Kerr, a freelance journalist, obtained figures from the force after submitting a Freedom of Information request.
An email response from the Force Information Unit, shown to the court, estimated around 40,000 police hours were spent on the investigation.
Staffing and other costs were identified in the message of September 28, 2008.
Kerr agreed when Sheridan said it came to “in excess of £1.1 million”.
Sisters Joyce Drummond and Irene Lang, former members of the SSP, told the jury in later evidence of a meeting they had with the party’s Colin Fox in Edinburgh in May 2006.
They said Fox told them he knew of a plot to “get” Sheridan within the party and asked for their help to “clear out” those who were against him.
Drummond, 48, from Glasgow, now a member of Solidarity, said: “He requested to meet us in Edinburgh and we met him.
“He said he knew of a plot amongst the SSP to get you.
“It was some kind of conspiracy going on.”
Both witnesses said Fox told them that at an SSP meeting in 2004, Sheridan denied allegations that he had attended a sex club, admitting only to a relationship with Anvar Khan “years ago”.
Lang, 44, from Glasgow, told Sheridan, who is conducting his own defence: “He said he knew there was a plot, that people were out to get you, and that he wanted to sort it.”
During cross examination by advocate depute Alex Prentice QC, child development officer Lang was asked about a letter of apology 14 members of her local Cardonald branch of the SSP wrote to the judge Lady Smith in May 2006.
The trial heard that the apology referred to contents of a motion drawn up by the members which said minutes of an SSP meeting, if they existed, should be destroyed.
Lang said the statement “wasn’t meant literally” and was only meant to send a message to the party.
Sheridan denies making false statements as a witness in the defamation action on July 21 2006. His wife Gail denies committing the same crime on July 31 2006 after being sworn in as a witness at the civil jury trial.
The trial before Lord Bracadale was adjourned until later today.