The sentences given to three teenagers for the manslaughter of Pc Andrew Harper will not be changed after the Court of Appeal dismissed challenges by the Attorney General and the trio.

Henry Long, 19, was jailed in July for 16 years and 18-year-olds Jessie Cole and Albert Bowers were handed 13 years in custody over the death of the Thames Valley Police traffic officer.

Pc Harper, 28, was caught in a strap attached to the back of a car driven by Long and dragged to his death down a winding country road as the trio fled the scene of a quad bike theft in Berkshire on the night of August 15 2019.

Long – the leader of the group – admitted manslaughter, while passengers Cole and Bowers were convicted of manslaughter after a trial at the Old Bailey.

All three were cleared of murder by the jury, which deliberated for more than 12 hours.

At a hearing in November, Attorney General Suella Braverman said the youths’ sentences should be increased, for an offence that was “as serious a case of manslaughter as it is possible to envisage”.

But lawyers representing Long, Cole and Bowers, who appeared by video-link from HMP Belmarsh, argued that their sentences were too long and should be reduced.

On Wednesday morning, Dame Victoria Sharp – sitting with Lord Justice Holroyde and Mr Justice William Davis – dismissed the Attorney General’s application to increase the trio’s sentences.

The decision was branded “disappointing” by Pc Harper’s widow Lissie who is campaigning for those who kill emergency workers to be jailed for life.

In a statement, she said: “I am of course disappointed with this outcome and ultimately feel along with the Attorney General and the majority of our country that these sentences are far too lenient, that they do not reflect the severity and barbarity of the crimes they committed.

“I continue to feel let down by our justice system and the inadequate laws that we have in place.”

The Court of Appeal also rejected Long, Cole and Bowers’ appeals against their sentences for manslaughter as “wholly unarguable”.

Cole and Bowers had also sought to appeal against their convictions for Pc Harper’s manslaughter, but this was also rejected as being “wholly unarguable”.

The Court of Appeal did reduce the sentences imposed on the pair for conspiracy to steal, from 38 months’ detention to an 18-month detention and training order given their ages at the time of the offence.

However, Dame Victoria said: “This does not affect the sentences for manslaughter and, because the sentences were concurrent, it does not affect the overall length of the sentences.”

She added: “The effect of our decision is that all three offenders remain convicted of the manslaughter of Pc Harper and the overall length of their custodial sentences remain unaltered.”