PC Harper was dragged for more than a mile behind a car driven by Henry Long. He was jailed for 16 years while passengers Albert Bowers and Jessie Cole were sentenced to 13 years’ imprisonment each.

Suella Braverman QC had claimed the sentences were unduly lenient but Dame Victoria Sharp, Lord Justice Holroyde and Mr Justice William Davis said that “mere disagreement with [the trial judge’s] decisions as to the nature and length of the appropriate sentences provides neither a ground for finding the sentencing to have been unduly lenient nor a ground for finding a sentence to have been wrong in principle or manifestly excessive”.

The Attorney General advanced the argument that the sentences were unduly lenient as the trial judge had failed to depart from the sentencing guideline.

The appeal judges said this was “to say the least, an unusual submission” as it implied the trial judge was required to deviate from the guideline.

“We think it regrettable that, in advancing that submission, the structure and ambit of the guideline were not addressed. Nor was any sufficient explanation given why it is contended that the judge was not merely entitled to depart from the guideline but positively required to do so.”

The judgment states: “This is not a case in which a departure from the guideline might be justified, for example, by the offenders having caused more than one death. In this case, the aggravating features relied on by the Attorney General were all taken into account by the judge either as part of his assessment of culpability or as an additional aggravating factor.

“In our judgment, the Attorney General’s argument does not make good the submission that it was not properly open to the judge to impose custodial terms of a length within the guideline offence range.”