A motorist who was jailed after ramming into a car full of teenagers, killing one of them, saw his appeals against conviction and sentence thrown out of court by top judges yesterday.

Shenol Ahmet, 19, from Friern Barnet, died, and his friend, Corey Holliday, from Bushey, suffered brain damage in the smash in The Common, Stanmore, in November 2009.

In September 2011, Abid Abu Kwaik, 40, of Anmersh Grove, Stanmore, was convicted of manslaughter and two counts of wounding and jailed for 12 years at Southwark Crown Court.

He took his case to the Court of Appeal but convictions and his prison term were upheld by judges.

Lord Justice Treacy said nothing in Kwaik's arguments meant the convictions were "unsafe" and said the seriousness of the attack justified the long prison sentence.

The court heard Mr Ahmet was driving from Barnet towards Bushey with Mr Holliday and another youth, Luke Hall, travelling as passengers when they came upon a restaurant run by Kwaik's brother.

Mr Holliday and Mr Hall threw eggs from the car at people sitting outside The Sahara Lodge, but Kwaik saw what happened, jumped into his Honda and gave chase.

Mr Ahmet died when he lost control of his Ford Fiesta and left the road, careering into a wooded area.

The prosecution alleged that Kwaik had pursued the teenagers, then used his car as a weapon, ramming them off the road.

On appeal, his lawyers argued that evidence given by a police officer, suggesting the likely cause of the crash was Kwaik using his car to apply force to the Fiesta, should not have been included in the trial.

Part of the opinion evidence was outside of the officer's area of expertise, Michael Holland QC told the court.

He also argued that fresh evidence in the form of a computer reconstruction cast doubt on how the crash may have occurred.

Giving judgment, Lord Justice Treacy, who heard the appeal with Mr Justice Royce and Mrs Justice Andrews, said the arguments did not affect the safety of the conviction.

Dismissing his appeal against the sentence, he continued: "In a case where a vehicle was used as a weapon of revenge to strike another vehicle at significant speed with the obvious serious risk that the victims' vehicle would run out of control, a severe sentence was required.

"That the source of his anger was the behaviour of the occupants of the Fiesta does not in our judgment serve to mitigate this offence.

"He had ample time to control his anger, both as he made his way to his car, then on the journey catching up with the Fiesta, and again after the handbrake turn. Each of those actions gave the opportunity to reflect and reconsider.

"The appellant's ultimate actions were out of all proportion to the insult offered by the egg throwing incident."

The appeals were dismissed.