A Government press officer leaked budget secrets to a Sun reporter in exchange for £750, a court heard.
Clodagh Hartley (pictured) is on trial at the Old Bailey accused of paying Her Majesty's Revenue and Customs press officer Jonathan Hall around £17,000 for story tips over a period of three years.
In March 2010, Hall gave the Whitehall editor information for an exclusive double page spread about Alistair Darling's budget before he stood up to deliver it to MPs, jurors were told.
Prosecutor Zoe Johnson QC said: "On the 24 March 2010 there was a big news story on pages eight and nine of the Sun exclaiming 'Don't Fudge It' with a cartoon and photograph of the then chancellor of the exchequer, Alistair Darling.
"This story was published on budget day and leaked an announcement that there was going to be a rise in fuel duty.
"As you would expect, the details of the budget are a closely guarded secret. You would expect the details would be announced to Parliament and not broadcast in advance in the newspapers and certainly not for money, for personal gain."
Johnson said a financial trail revealed that Hall was paid £750 for the exclusive story at the request of Hartley.
He was also paid £500 for a story in December 2009 headlined "£1m celeb Ads", which revealed that celebrities including Kelly Brook were being paid as part of a £1.3 million tax payer funded TV campaign publicising the government website Directgov, the jury was told.
Hall, who joined HMRC in 2009, received more than £4,000 directly from News International between April 2008 and May 2010.
Then, at Hartley's suggestion, he used his girlfriend Marta Bukarewicz's account to channel more than £13,000 between June 2010 and July 2011 in order to "cover his tracks", the court heard.
Bukarewicz transferred most of the money to Hall but kept £845 for her role in the "unlawful agreement", Johnson said.
She told jurors: "This is not a trial involving whistle-blowing in a noble cause. It is a case in which Hall, the HMRC press officer, was motivated by greed and Miss Hartley, the journalist, was motivated by acquiring the next big scoop or exclusive.
"Many of you will have sympathy for journalists who expose mismanagement and inefficiency in government departments but that is not what this case is about."
She added: "This prosecution is not an attack upon the freedom of the press to report on matters that may interest the public or are in the public interest.
"The freedom of the press, any freedom of expression of citizen or press, does not include an entitlement to break the law."
The jury was told that Hall has accepted that he supplied stories to Hartley for which he was paid but was not in the dock.
Hartley, 40, of Brockley, south east London and Bukarewicz, 45, of Kentish Town, north west London, deny conspiracy to commit misconduct in public office.