A sixth-form student has been jailed for two years and eight months after admitting throwing a fire extinguisher from a roof in a riot.
Edward Woollard, 18, joined protesters who stormed inside the Millbank complex in London, which houses the Tory Party headquarters, on November 10.
He was filmed throwing an empty metal fire extinguisher from a seventh-floor rooftop as hundreds of people gathered in a courtyard below.
Woollard, of Dibden Purlieu, Hampshire, will serve at least half of his sentence for violent disorder in a young offenders institution.
Judge Geoffrey Rivlin QC praised the teenager's mother for encouraging him to give himself up to police after he was pictured by media organisations during the rioting.
The judge said: "It is deeply regrettable, indeed a shocking thing, for a court to have to sentence a young man such as you to a substantial term of custody. But the courts have a duty to provide the community with such protection from violence as they can and this means sending out a very clear message to anyone minded to behave in this way that an offence of this seriousness will not be tolerated."
He added: "The right of peaceful protest is a precious one. Those who abuse it and use the occasion to indulge in serious violence must expect a lengthy sentence of immediate custody.
"Nevertheless I shall take into account in your favour the extraordinary and courageous conduct of your mother, which resulted in you giving yourself up to the police so quickly."
