Six allegations of perjury against ex-MSP Tommy Sheridan were dropped as the prosecution concluded its case.
Prosecutors told jurors the deletion of significant parts of the indictment would allow the remaining issues to be "sharply focused".
Evidence in the trial came to an end on Friday, when Mr Sheridan's wife Gail was acquitted of perjury.
Mr Sheridan, 46, denies lying in his defamation action against the News of the World in 2006.
He was awarded £200,000 following the civil case he launched after the newspaper printed an article claiming he was an adulterer who visited swingers' clubs.
At the start of the perjury trial, the former leader of the Scottish Socialist Party (SSP) had faced more than a dozen claims of lying under oath.
Last month the Crown announced it would not pursue Mr Sheridan over two allegations of lying and on Monday prosecutor Alex Prentice QC said a further six allegations would be dropped.
Mr Prentice explained he wanted to "prune" down the indictment because it was actually "quite a straightforward case".
There is now one charge of perjury against Mr Sheridan, consisting of six allegations.
Beginning his closing speech, Mr Prentice told the jury at the High Court in Glasgow that although there were no victims, such as there are in cases of murder or rape, perjury was a serious crime nonetheless.
The advocate depute said: "Our whole system of justice falls apart if perjury is acceptable behaviour.
"It is not acceptable and should never be acceptable in a dignified and mature democracy.
"If we let perjury pass without action, we let ourselves down."
The advocate depute denied that the case had been driven by the News of the World, saying: "I do not represent any individual or corporation.
"I do not represent the News of the World. I do not represent any editor, journalist, the Scottish Socialist Party, nor the police."
Mr Prentice said the reason he emphasised his independence as a prosecutor was because the defence was suggesting the case against the former SSP leader was a grand conspiracy.
This, Mr Prentice suggested to the jury of 12 women and two men, was "just fantasy".
The prosecution concluded its case again by again playing the jury a tape which allegedly records Mr Sheridan admitting to visiting a sex club.
The tape was sold to the News of the World by Mr Sheridan's best man George McNeilage, who said he secretly recorded the politician in Mr McNeilage's home in Pollok, Glasgow, in 2004.
The QC said the video backed up evidence that Mr Sheridan had been to the swingers' club in Manchester.
The accused smiled and shook his head on a number of occasions as the video was played.
Mr Prentice told the jury: "I ask you ladies and gentlemen to conclude on the evidence that Mr Sheridan did indeed admit attending."
Crown counsel also said the recording rebutted allegations that the case was "all a big conspiracy", involving the press or the SSP.
If that were the case, Mr Prentice asked, how could the defence explain a number of details in the tape some of which apparently undermined stories in the News of the World.
He paused the tape on several occasions to ask "if this were a conspiracy, why would you include that?"
Referring to claims by witnesses surrounding the alleged visit to the sex club, Mr Prentice said: "You have experience of life and of human affairs and if you look at all these things together is there not a very strong picture emerging?"
The court has heard from three witnesses who claimed they visited the club with Mr Sheridan - Anvar Khan, Katrine Trolle, and Gary Clark.
Mr Prentice suggested that "it took great courage on the part of Gary Clarke" to face the jury and admit that he had visited a sex club.
What emerges, said the advocate depute, "is a very convincing and compelling body of evidence to show that Mr Sheridan went to Cupids with those others".
He concluded by inviting the jury to find Tommy Sheridan guilty of perjury.
Mr Sheridan, who is representing himself in court, is expected to make his closing speech on Tuesday afternoon.
The judge, Lord Bracadale, will then address the jury on points of law before they retire to consider their verdict.