The son of Pink Floyd guitarist David Gilmour admitted today going on the rampage at a student fees protest.
Charlie Gilmour was warned he could face a jail term after pleading guilty to violent disorder - but he was granted bail until July to give him time to complete Cambridge University exams.
Gilmour, who was accused of a string of offences during the riot on December 9, entered a non-specific guilty plea as he appeared at Kingston Crown Court, south west London.
The 21-year-old, from West Sussex, has yet to specify whether he admits leaping on the bonnet of a car carrying royal protection officers escorting the Prince of Wales and his wife to the Royal Variety Performance.
Judge Nicholas Price QC granted Gilmour conditional bail as he adjourned proceedings until July 8.
He said he would give Gilmour's legal team time to decide the specifics of the plea before arranging another hearing.
Gilmour, a former model, wore a grey suit and dark tie as he spoke to confirm his name and enter a guilty plea.
Judge Price told Gilmour: "You have accepted counts of a serious matter and it may well be the course of one of immediate custody.
"This matter will come back to this court on July 8."
Gilmour is accused of smashing a window at a high street store and throwing a rubbish bin at the royal convoy.
The bin missed the royal couple but hit another car, it is alleged.
Gilmour had been accused of stealing a mannequin leg, but that charge was withdrawn.
He was among thousands of people who protested in Trafalgar Square and Parliament Square on December 9 and was photographed hanging from a Union flag on the Cenotaph during the march.
He issued an apology the day after the demonstrations, describing it as a "moment of idiocy", and adding that he did not realise the Whitehall monument commemorated Britain's war dead.
Gilmour's biological father is poet and playwright Heathcote Williams but he was adopted by the rock star when his mother, writer and journalist Polly Samson, remarried.
Releasing a statement in the wake of his Cenotaph antics, Gilmour said: "I feel nothing but shame. My intention was not to attack or defile the Cenotaph. Running along with a crowd of people who had just been violently repelled by the police, I got caught up in the spirit of the moment."
David Gilmour's former bandmate Roger Waters lost his father in the Second World War and has written about his loss extensively throughout his career, including a number of Pink Floyd songs.
Gilmour has been on the books of modelling agency Select Model Management and has also tried his hand as a journalist, but is now completing a history degree at Girton College, Cambridge.
His father is admired as one of the world's finest guitarists and his Floyd album Dark Side Of The Moon is one of the biggest-selling releases of all time.
In an interview last year, Gilmour talked about being bought two Savile Row suits before he headed off to university.
A Cambridge University spokesman has said the matter is "for the civil authorities".
Gilmour, who is banned from the City of Westminster as part of his bail conditions, has Cambridge exams to sit in June, the court heard.
The judge added: "The fact that I am granting you bail is of no indication whatsoever that you will be dealt with in a non-custodial way.
"You must understand that your plea of guilty to violent disorder is a serious matter and it may be that the proper course would be one of immediate custody."
Gilmour made no comment to reporters as he left court.