The families of two murdered French students today criticised the decision not to refer their sons' killers' sentences to the Court of Appeal.
The Attorney General Baroness Scotland said the life terms given to Dano Sonnex and Nigel Farmer, with minimum terms of 35 and 40 years, were not unduly lenient.
The two men were jailed for the "sadistic" murders in June last year of Laurent Bonomo and Gabriel Ferez in New Cross, south east London.
Mr Ferez's mother Francoise Villement, 46, said: "We hoped that the sentence would be longer. It's not right.
"This won't change anything for me because nothing can bring back my son but it was important that the sentence be longer in order to send a message to society.
"For society's sake, it's a shame."
Mr Bonomo's mother Lydie Bonomo, 53, said: "I'd have preferred them to have received a more final sentence but I'm not surprised by this. I thought it would be the case."
The two students, both 23, died in an "orgy of bloodletting" after being tied up by the drug-fuelled killers and tortured for nearly three hours.
Sonnex and Farmer attacked their semi-naked victims in Mr Bonomo's flat in New Cross, south east London, after climbing in through an open window.
After stealing bank cards and mobile phones, they launched an "inhuman" attack of "brutal and sustained ferocity" on the two 23-year-olds, the Old Bailey heard.
Mr Bonomo was stabbed 194 times and Mr Ferez suffered 50 knife wounds, some of them after his death.
Justice Secretary Jack Straw apologised to the families of the two men last month after it emerged a string of failures throughout the justice system left Sonnex free to kill when he should have been in prison.
The families of the two students have said they wanted their killers to be given "whole life" terms - meaning they would die in prison.
But today Lady Scotland said there was "no prospect" that the Court of Appeal would increase the terms.
She said: "These sadistic murders were truly appalling and those closest to the victims have my deepest sympathy.
"In handing down life sentences, the judge acknowledged he had the option of imposing a 'whole life tariff', meaning an offender can never be released, but these sentences are rarely used.
"However, as he explained that he was not going to use this sanction, my remit was to look at whether the very lengthy minimum periods of imprisonment could instead be described as unreasonable and unduly lenient.
"Having taken account of all relevant papers in the case - including the statements of both families and the impact the murders have had on them - I believe the sentences could not be said to fall outside the proper range and that there is no prospect that the Court of Appeal would increase them.
"Even after the minimum terms are served, the offenders will remain in prison unless and until the Parole Board judges them safe to be released on licence. The judge felt this time may well never come."Reuse content