The prison sentences handed to Pc Andrew Harper’s killers have been referred to the Court of Appeal by the Attorney General for judges to decide whether they were too lenient.

Suella Braverman was asked to review the terms after Henry Long, 19, Albert Bowers and Jessie Cole, both 18, were jailed for manslaughter at the Old Bailey last month.

Pc Harper, a Thames Valley Police traffic officer, got caught in a crane strap attached to the back of a car driven by Long as the teenagers fled the scene of a quad bike theft in Berkshire.

He was dragged to his death on August 15 last year along dark country lanes.

Long was sentenced to 16 years in prison, while Bowers and Cole were handed 13-year jail terms by Mr Justice Edis after they were each cleared of murder.

The case was referred to the Attorney General under the scheme which allows crime victims, their families, prosecutors or the public to ask for a review of sentences they believe are too low.

Ms Braverman can only ask the Court of Appeal to review a sentence she considers to be “unduly lenient”, usually in cases where the judge is believed to have made a mistake or imposed a sentence outside the range of what is reasonable.

She said on Friday: “This was a horrific crime which resulted in the death of a much-respected police officer while he was on duty, protecting his community.

“Having personally considered the details of this shocking case, I have decided to refer the sentences of Pc Andrew Harper’s killers to the Court of Appeal.

“Attacks made against emergency workers will not be tolerated and offenders should be punished with the greatest severity for such heinous crimes.”

On Wednesday, Bowers and Cole lodged applications with the Court of Appeal seeking permission to challenge their convictions and sentences in a move described by Pc Harper’s mother Debbie Adlam as a “kick in the stomach”.

Their case is likely to take place on the same day as Court of Appeal judges consider whether their sentences should be increased at a hearing later this year.

Ms Adlam told the PA news agency on Friday: “I’m pleased to see that the Attorney General Suella Braverman has taken the important step of referring the sentences to the Court of Appeal under the Unduly Lenient Sentence scheme.

“My family and I know that the whole nation stands with us in outrage at the sentences handed down to my son’s killers.

“We can only hope that a fairer outcome is reached by the Court of Appeal to deliver the justice that Andrew deserves.

“As a family, we will not stop campaigning until our blue light heroes are safer as they step out each and every day to protect us as a society.”

Pc Harper’s widow, designer Lissie Harper, 29, has launched a campaign for a change to the law which would see those convicted of killing emergency workers jailed for life.

She said: “This is great news and we thank the Attorney General for her swift decision.

“The sentences for Andrew’s killers did not match their heinous crime.

“It was not justice and it needs to be addressed. Police officers need to be properly protected by the judicial system. And there must be appropriate punishments for those who would kill police officers.

“We now await the outcome with interest and in the meantime we will continue to campaign for Harper’s Law, which is calling for those who kill emergency services workers to spend the rest of their lives in prison.

“I would also like to thank the public for their continued and unstinting support.”

More than 350,000 people have signed an online petition calling for Harper’s Law and she is trying to secure a meeting with Home Secretary Priti Patel.