Three men who stabbed the schoolboy Ben Kinsella to death were jailed for life yesterday after being warned that they face retribution in prison for the murder.

Jade Braithwaite, 20, Juress Kika, 19, and Michael Alleyne, 18, have all received letters from prison authorities alerting them that they are marked men.

Each will spend at least 19 years in jail for the murder of the 16-year-old brother of the former EastEnders actress Brooke Kinsella.

Applause erupted from the public gallery of the Old Bailey as the killers were led down to the cells in handcuffs. Police had to intervene as friends of the defendants clashed with friends of Ben as they shouted out “Bye” and “Enjoy your porridge”.

Ms Kinsella, who played Kelly Taylor in the BBC soap, clapped once but otherwise kept silent with the rest of her family in the well of court.

Speaking outside court after the hearing she said of the 19-year minimum tariff: “It’s just little more than Ben lived, so it really is not good enough.”

Sentencing the killers, Brian Barker QC, the Common Serjeant of London, said: “Ben Kinsella was 16 when he died. Your blind and heartless anger that night defies belief. He had in front of him a lifetime of promise. You have taken all that away from him in a brutal, cowardly and totally unjustified attack.”

“It reflects yet again the futility of carrying and use of knives by some people. Crimes like these generate outrage in all like minded people.”

Earlier, lawyers for the three killers confirmed that they had received letters warning them they may be under threat from members of a notorious crime family.

Nerida Harford-Bell, for Braithwaite, said: “Jade understands he is a marked man. His mother, grandmother and aunt are in process of moving from their addresses to an entirely different area.”

Sallie Bennett-Jenkins, for Alleyne, said: “He has received a letter that will have an impact for more than many years. It is an unusual step but one he is going to take very, very seriously.”

James Nichol, solicitor advocate for Kika, said of his letter: “It is being taken seriously.”

Ben, who wanted to become a graphic designer, was stabbed 11 times after becoming the innocent victim of an argument. He had been celebrating the end of his exams at Shillibeers bar in Holloway, north London, when he was attacked in the early hours of June 29 last year.

After a mass brawl that had not involved Ben, Braithwaite recruited Kika and Alleyne to get revenge for being “disrespected”. They chased the rival group of youths down the street and picked on Ben when he failed to run away.

The straight-A student was kicked to the floor and stabbed eleven times in five seconds as he pleaded: “I’ve not done anything wrong.”

He was the 17th teenager to be murdered in London last year.

Kika was wanted by police for a stabbing and robbery in Islington days earlier but was only tracked down when he was arrested for the murder on June 30.

Alleyne was on licence after being released from an 18 month prison sentence for drug dealing. Braithwaite had served a 12-month sentence for attempted robbery in 2006. He later blamed Alleyne and Kika for the stabbing, sparking ugly scenes in court as the defendants turned on each other.

Kika and Alleyne, both from Holloway, north London, and Braithwaite from Bow, east London, all denied murder.

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