The legality of whole life sentences has been upheld by the court of appeal which refused to cut the prison term imposed on a man who "sadistically tortured" his former partner Christine Chambers and shot dead their two-year-old daughter, Shania.
Though the panel of five judges said David Oakes should stay behind bars for the rest of his life, the court did overturn similar tariffs on two notorious offenders, Danilo Restivo and Michael Roberts.
The judgment, written by the lord chief justice, Lord Judge, comes as the upper chamber of the European court of human rights is due to hear a challenge by three other convicted British murderers, including Jeremy Bamber, to the legitimacy of lifetime terms.
In its judgment, the appeal court said imposing such orders was not incompatible with article 3 of the European convention on human rights, which prohibits torture and inhuman or degrading treatment and punishment.
"The whole life order, the product of primary legislation, is reserved for the few exceptionally serious offences in which, after reflecting on all the features of aggravation and mitigation, the judge is satisfied that the element of just punishment and retribution requires the imposition of a whole life order," Lord Judge said. "If that conclusion is justified, the whole life order is appropriate: but only then. It is not a mandatory or automatic or minimum sentence."
On Oakes, 51, of Steeple, Essex, the judges said: "[He] did not simply explode into violence as a result of the stresses and strains of the breakdown of his relationship. Rather, he decided to revenge himself on Christine Chambers.
"He did not merely plan to kill her and their daughter, but he planned and then carried out his deliberate intention to make the death of his former partner the most terrifying and agonising ordeal that he could envisage …
"He was utterly merciless, and took pleasure at her prolonged suffering. Thereafter, in cold blood, he deliberately executed their daughter, as she was screaming with fear at witnessing what he had been doing to her mother."
The five judges reduced the whole-life order on the "Bermondsey Beast" rapist, Roberts, to a minimum 25 years. Roberts, who terrorised elderly women in the south London district, was jailed in January and told he would live out his days behind bars. One of his victims was aged 83. He evaded justice for 15 years but was captured after a cold case review by Scotland Yard.
Restivo had his whole-life tariff reduced to 40 years. The hair fetishist was given a whole-life tariff in June last year for the murder and mutilation of a mother-of-two in Bournemouth.
The Italian national, now 40, was found guilty by a jury at Winchester crown court of the 2002 murder of Heather Barnett, 48.
The panel also upheld the 30-year minimum term imposed on Kiaran Stapleton, who was jailed for life after killing a stranger in the street.
The minimum term imposed in the case of Restivo is the equivalent of an 80-year determinate term, with the 25 years in the case of Roberts being the equivalent of 50 years.