Whole-life jail sentences without any prospect of release amount to inhuman and degrading treatment of prisoners, the European court of human rights has ruled.

The landmark judgment will set the ECHR on a fresh collision course with the UK government but does not mean that any of the applicants – the convicted murderers Jeremy Bamber, Peter Moore and Douglas Vinter – are likely to be released soon.

In its decision, the Strasbourg court said there had been a violation of article 3 of the European convention on human rights, which prohibits inhuman and degrading treatment.

The judgment said: "For a life sentence to remain compatible with article 3 there had to be both a possibility of release and a possibility of review."

The court emphasised, however, that "the finding of a violation in the applicants' cases should not be understood as giving them any prospect of imminent release. Whether or not they should be released would depend, for example, on whether there were still legitimate penological grounds for their continued detention and whether they should continue to be detained on grounds of dangerousness. These questions were not in issue."

The appeal was brought by Vinter, who murdered a colleague in 1996 and after being released stabbed his wife in 2008; Bamber, now 51, who killed his parents, his sister Sheila Cafell and her two young children in 1985; and Moore, who killed four gay men for his sexual gratification in 1995.

The judges in the grand chamber at Strasbourg, the appeal court above the ECHR, found by a majority of 16 to one that there had been a violation of human rights. The judges awarded Vinter €40,000 (£34,500) for his legal costs.

Their decision means that the government will now be under pressure to introduce a formal review of whole-life sentences after 25 years. The current law governing release of life prisoners in England and Wales was unclear, the judges said.

Those on a whole-life term can be freed only by the justice secretary, who can give discretion on compassionate grounds when the prisoner is terminally ill or seriously incapacitated.

The ruling comes shortly after the home secretary, Theresa May, voiced her frustrations with the European courts in the Commons in the wake of the lengthy fight to deport the radical cleric Abu Qatada from the UK.

In its judgment, the grand chamber said: "The need for independent judges to determine whether a whole-life order may be imposed is quite separate from the need for such whole-life orders to be reviewed at a later stage so as to ensure that they remain justified on legitimate penological grounds."

It added: "Given that the stated intention of the [2003 Criminal Justice Act] was to remove the executive entirely from the decision-making process concerning life sentences, it would have been more consistent to provide that, henceforth, the 25-year review [of whole-life sentences], instead of being eliminated completely, would be conducted within a wholly judicial framework rather than, as before, by the executive subject to judicial control."

The new British judge on the court, Paul Mahoney, pointed out in his comments that the UK government was "of course free to choose the means whereby they will fulfil their international treaty obligation" to abide by the judgment.

In response to the decision, Bamber said: "I am the only person in the UK who was [retrospectively] given a life tariff on a majority verdict that maintains innocence. The verdict today seems in so many ways to be hollow, as I am still serving a prison sentence for a crime I did not commit. My whole-life order has now been given a system of reviews, but there is no provision for someone who is wrongly convicted to prove that they are worthy of release, such hope is in reality no hope at all.

"Reviews and parole hearings are subject to a risk assessment to gauge dangerousness and this is influenced by the inmate's confession, remorse and rehabilitation for reintegration back into the community. In my case I do not fit the criteria for parole on this basis.

"The justice system, despite the investment in the Criminal Cases Review Commission, still refuses to accept that there are prisoners who are innocent of the crimes they have been convicted of and this comes into conflict with sentence reviews.

"While there are some people who have been released at the end of their sentence and still maintained innocence, such as Eddie Gilfoyle and Susan May, it is unlikely that I would ever be released without my conviction being overturned in a court of law simply because of the high-profile nature of my case. As is always, the law does not apply if it assists me in any way."

Bamber's statement was released by those campaigning to overturn his conviction for killing five members of his family at a farmhouse in Essex in 1985.

During the original hearing in Strasbourg, Pete Weatherby QC, who represented the three claimants, told the court: "The imposition of a whole-life sentence crushes human dignity from the outset, as it removes any chance and therefore any hope of release in the future. The individual is left in a position of hopelessness whereby he cannot progress whatever occurs."

Commenting on the decision, Rebecca Niblock, a criminal law solicitor at Kingsley Napley LLP, said: "No doubt there will be renewed calls to pull out of the European convention on human rights and repeal the Human Rights Act. Yet Theresa May would do well to keep a sense of proportion: a right to have the sentence reviewed is quite different from a right to be released, and the number of prisoners affected is tiny – 49."

"England and Wales lag behind other European countries in the use of the whole-life sentence – the only other EU country which uses it is Holland. The repeated calls to withdraw from the European convention carry a huge risk of undermining the UK's reputation abroad. There is only so much the UK can say to other countries about their human rights records when they show disdain for judgments which go against them at Strasbourg.

"Making political capital at the expense of the rule of law is a dangerous game."