Orders preventing prisoners from ever being released from jail do not breach their human rights, leading judges have ruled.
A specially-constituted panel of Court of Appeal judges made their announcement as they gave decisions in challenges brought by killers and rapists over the imposition of "whole-life" tariffs in their cases.
Giving the ruling, Lord Chief Justice Lord Judge said the whole-life order "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".
He added: "If that conclusion is justified, the whole-life order is appropriate, but only then. It is not a mandatory or automatic or minimum sentence."
Although the appeal judges overturned whole-life orders in the cases of a murderer and two rapists, they said the imposition of such orders was not incompatible with Article 3 of the European Convention of Human Rights, which prohibits torture and inhumane or degrading treatment and punishment.
The ruling comes a week before an appeal by killer Jeremy Bamber and two other murderers, who will be seeking to overturn their whole-life terms at the Grand Chamber of the European Court of Human Rights.
The Court of Appeal judges, sitting in London, allowed an appeal by hair fetishist Danilo Restivo, who murdered and mutilated a mother of two. An order that blocked his release was replaced with a minimum term of 40 years - the equivalent of an 80-year determinate term. The court also reduced the whole-life order imposed on "Bermondsey Beast" rapist Michael Roberts to a minimum term of 25 years, equivalent to a 50-year determinate sentence.
And the judges also allowed an appeal by David Martin Simmons, 40, who pleaded guilty to rape and false imprisonment and was sentenced to life in December 2004, replacing his whole-life order with a 10-year minimum. But the court refused to quash the whole-life order in the case of killer David Oakes, who "sadistically tortured" his former partner before shooting her and their two-year-old daughter.
As well as the whole-life cases, the judges dismissed a challenge by Kiaran Stapleton against the 30-year minimum term imposed when he was jailed for life after he "executed" a stranger in the street.
The men are all still subject to life sentences. Those with a minimum term can apply for parole once that has expired, but they would not be released until they are deemed to no longer pose a threat to the public.