The trial of a reporter accused of paying a government official for stories "is not about The Sun newspaper as an institution", the Old Bailey heard.
Clodagh Hartley, 40, is accused of arranging payments of £17,475 to HMRC press officer Jonathan Hall over a period spanning more than three years, in exchange for the information.
Hall, 43, convinced his girlfriend to let him use her account for receiving thousands of pounds from News International, the Old Bailey has heard.
He is said to arranged with Hartley to switch the payments to his partner Marta Bukarewicz's bank account, in a botched attempt to hide his tracks.
Both Hartley and Bukarewicz, 45, deny conspiracy to commit misconduct in public office.
Yesterday prosecutor Zoe Johnson QC made her closing speech.
"Members of the jury, this is case about a public official, his girlfriend and a journalist.
"It is not a case about the press. It is not about The Sun newspaper as an institution.
"Millions of readers enjoy The Sun and it is an established and valued member of our newspaper community.
"Everyone agrees that the press plays a vital role in our society and whatever decision you come to in this case, that role remains paramount.
"We all admire those journalists who risk their lives to bring us the truth about horrors occurring in other countries and work to expose corruption and criminality in our institutions and offices of state."
Johnson said Hartley's only motivation had been "to steal a march over competitors" by paying Hall, she said.
"Press officers [at] HMRC are public officials. There is no doubt or question about that.
"They are the holders of public office. And what does that mean?
"That they serve the public – and you are representatives of the public.
"They do not serve the press. And it is accepted as we know, that Jonathan Hall was a public official and that in many ways that will be the starting point for you in your consideration of the case."
News International invoices sent to Bukarewicz "make it clear" she was complicit, the prosecutor said.
The letters even stated the titles of stories for which she was ostensibly being paid.
"The titles of the stories rather give the game away, we suggest."
Johnson reminded jurors she thought Hall was a "protected source".
"Protected from who and protected why?", asked Miss Johnson.
She said Bukarewicz was perfectly aware of Hall's misconduct but it was "raining cash into her account".
Johnson said Hartley had tried to paint herself as "the down-trodden woman, terrified of the ogre that is [her senior colleague]".
"Was that the role of Miss Hartley? We suggest not. The real Clodagh Hartley was the ambitious journalist…always searching for the next exclusive.
"If you determine Hall was corrupt.. then was Miss Hartley the corruptor?"
Referring to Roy Greenslade's evidence, she said: "The prosecution do not question, because we accept, that journalists perform a vital role in society, to reveal the totality of information.
"There is and always has been a tension between government and the press and that tension is a pillar of our our democracy."
She added that Hartley was always under pressure, fighting a "daily battle to get her stories into the paper".
The prosecutor said that "to approach this case as saying government – baddies, press – goodies, is a simplification and won't help you to resolve the real issue in this case".
She said the prosecution was not about "the press as some organ, some body, some group, it is about the three people involved in this case case their relationship with each other".
"Have you decided whether the stories were sufficiently important to excuse what we suggest is the inexcusable?
"This is not Watergate…this is not Wikileaks. It is easy money for lazy journalism."
She referred to an internal email from Sun journalist John Sturgis, who commented on a story Hartley wrote about a £1m advertising scheme for a government website.
"The Directgov campaign was a bargain compared to what Hall was being paid.
"Miss Hartley told us the thought that the worst that could happen to Hall was that he would get the sack.
"In other words, she knew that he was doing something so serious it could lead to his dismissal.
Johnson said Hall had shown "traitorous disloyalty" to HMRC and was not a whistleblower.
"If everyone did what Mr Hall was doing, it would be chaos."