Wayne Couzens is still set to die in prison after he lost his bid to reduce his sentence at the Court of Appeal.

In May, senior judges heard challenges or appeals to the prison sentences of five convicted killers, including the whole-life terms of former Sellafield officer Couzens.

Couzens served at the nuclear site as an officer under the Civil Nuclear Constabulary for eight months in 2011. The Civil Nuclear Constabulary (CNC) is the armed police force in charge of protecting civil nuclear sites.

On Friday, the Lord Chief Justice Lord Burnett and four other judges refused to lower Couzens' sentence.

Last year, the former officer was handed a whole life term for the rape and murder of 33-year-old Sarah Everard, the first time the sentence had been imposed for a single murder of an adult not committed in the course of a terror attack.

Appealing against the whole-life term, Couzens' lawyers argued he deserved "decades in jail" but said a whole-life term was excessive.

However, in a summary read out in court, Lord Burnett said that the sentencing judge was entitled to impose a whole life order due to the facts of Couzens' case.

He said: "The issue at the heart of the appeal, is whether this murder, with its unique features, justified the judge's overall conclusion that it merited a whole life order. We have concluded that it does, albeit we would, with respect, arrive at this conclusion by a different route from the judge."

Lord Burnett continued: "This was, as the judge said, warped, selfish and brutal offending, which was both sexual and homicidal.

"It was a case with unique and extreme aggravating features. Chief amongst these, as the judge correctly identified, was the grotesque misuse by Couzens of his position as a police officer, with all that connoted, to facilitate Ms Everard's kidnap, rape and murder.

"We agree with the observations of the judge about the unique position of the police, the critical importance of their role and the critical trust that the public repose in them."

Lord Burnett said that while the sentencing starting point in Couzens' case would be a minimum term of 30 years, he continued: "Having regard to its aggravating features we are in no doubt that its seriousness is so exceptionally high such that a whole life order rather than a minimum term order should be made.

"We consider this to be the correct route to a just result in this case.

"It provides for its unique and defining feature, which was that Couzens had used his knowledge and status as a police office to perpetrate his appalling crimes against Ms (Sarah) Everard and for the extensive and extreme nature of the other aggravating features which were present: the significant and cold-blooded planning and pre-meditation; the abduction of Ms Everard; the most serious sexual conduct; the mental and physical suffering inflicted on Ms Everard before her death; and the concealment and attempts to destroy Ms Everard's body.

"We agree with the judge that having determined there should be a whole life order, given the misuse of Couzens' role as a police officer and the serious aggravating features of the offending the guilty pleas did not affect the outcome."