THREE teenagers who killed PC Andrew Harper will have their sentences challenged as being "unduly lenient" at the Court of Appeal as they also mount their own appeals against their jail terms.

Henry Long, 19, was jailed for 16 years and 18-year-olds Jessie Cole and Albert Bowers were each jailed for 13 years for the manslaughter of Thames Valley Police (TVP) traffic officer PC Harper in July.

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PC Harper, 28, was caught in a crane 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 West Berkshire on the night of August 15 2019.

Long admitted PC Harper's manslaughter while Cole and Bowers were both convicted of manslaughter after trial, with all three cleared of murder by an Old Bailey jury which deliberated for more than 12 hours.

At the Court of Appeal in London on Monday, lawyers for the Attorney General will argue that the sentences the three teenagers received were "unduly lenient" and should be increased.

At the same hearing, the trio will appeal against the length of their sentences while Cole and Bowers will apply to appeal against their convictions - a move previously described by PC Harper's mother Debbie Adlam as a "kick in the stomach".

PC Harper and his wife Lissie had been married for just four weeks when he and a TVP colleague responded to a late-night burglary in Sulhamstead in August last year.

Mrs Harper has since campaigned for Harper's Law, which would mean those who kill emergency workers are jailed for life, and met with Home Secretary Priti Patel and Justice Secretary Robert Buckland earlier this month.

At their trial, the trio's defence claimed the incident was a "freak event" that none of them could have planned or foreseen.

But the prosecution said the defendants must have been aware PC Harper - at more than 6ft and weighing 14 stone - was being dragged to his death.

Sentencing the defendants in July, Mr Justice Edis said: "Nothing which I can do, or could have done, if there had been a conviction for murder, can restore Andrew Harper to his loving wife and family, or to the public he served so well.

"His devastating loss in these terrible circumstances will follow his family forever."

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The judge added: "You killed a talented and brave young police officer who was going above and beyond his duty in order to provide a public service, and you did so because you had deliberately decided to expose any police officer who got in your way to a risk of death.

"You decided that your freedom to commit crime was more important than his life."

The hearing before Dame Victoria Sharp, Lord Justice Holroyde and Mr Justice William Davis is being heard at the Royal Courts of Justice in London and begins at 10.30am.