The 73-year-old is accused of assaulting the 17-year-old at his Mayfair offices in London between October 1981 and May 1982.
He allegedly locked the girl in his office and forced her to engage in a sexual act with him, a jury at Southwark Crown Court in London was told. When there was a knock on the door, he put his finger to his lips to try to keep her quiet, it is claimed.
Prosecutor Rosina Cottage said he “used his position of power” to “embarrass” and “humiliate” the young victim.
“The defendant is a sexual bully who took advantage of his position of power over the youth of the victim to engage in sexual activity she made it plain she did not want to do,” she added. “The defendant ignored her wishes and persisted in his actions, knowing she did not consent.”
He apparently left “explicit” Polaroid photographs of women on his desk for the teenager to see. “Many displayed a man’s hand which she believed was the defendant,” Ms Cottage added.
“Clearly they were there for her to see.”
Mr Clifford also made “personal remarks” about the victim’s appearance and how short her skirt was, the court was told.
Mr Clifford, formerly of Hersham, Surrey, is charged under Operation Yewtree, the Met Police investigation set up in the wake of the Jimmy Savile scandal.
Some of the biggest names in show business, including pop mogul Simon Cowell, and boxer Muhammad Ali were represented by Mr Clifford during his career, which spanned more than 40 years.
Mr Clifford appeared in the dock wearing a blue suit, white shirt, blue and red spotted tie, and glasses, with a beard, and followed proceedings through a hearing loop.
Mr Clifford allegedly exposed himself to the teenager, “waved” his genitalia in her face, and said: “It’s only a bit of fun.”
Ms Cottage said he “went to the door of the office and locked it. They were the only two in the office”.
“He stood between her and the door and unzipped his trousers,” she added.
Mr Clifford then forced the girl to put her hand on him and perform a sex act, the court was told.
Ms Cottage continued: “She began to panic but didn’t know what to do. She was terrified and had no idea what to do. She kept saying she didn’t want to do it and didn’t want to miss her train.” She added: “She felt she had no choice but to comply.”
When there was a knock at the door, Mr Clifford “motioned with his lips to be quiet”, the jury heard.
He stormed off after the teenager called out “just a minute”, Ms Cottage said.
Mr Clifford denies that the incident took place and claimed the allegation was “made up so that she could try and claim compensation”.
The trial continues.