The sentences handed out to Gary Dobson and David Norris for the racist murder of black teenager Stephen Lawrence will not be referred to the Court of Appeal for being "unduly lenient", the attorney general has decided.
The announcement follows news earlier this week that both men, who were sentenced at the Old Bailey last month, are seeking to challenge their convictions.
Attorney General Dominic Grieve said the murder of the black teenager in 1993 was "a despicable and appalling crime."
"Justice was long delayed and I can fully understand why some people are unhappy that the minimum terms handed down were not longer," he said on Wednesday.
"However, having considered the sentences carefully I have come to the conclusion that the minimum terms are within the appropriate range of sentences, bearing in mind the offenders' ages at the time of the crime, and therefore I have decided not to refer them to the Court of Appeal.
"It is perhaps worth emphasising that the terms are the minimum periods that will actually be served.
"Dobson and Norris will not be released unless and until the Parole Board considers they do not pose a risk."
Dobson, 36, has to serve at least 15 years and two months before he becomes eligible to apply for parole.
Norris, 35, was given a minimum of 14 years and three months for the murder, which the trial judge, Mr Justice Treacy, said was a "terrible and evil crime".
He urged police not to "close the file" on catching the rest of the killers after the court heard that a gang of five or six white youths set upon the A-level student Stephen in Eltham, south east London, in 1993.
Mr Justice Treacy said the murder was committed "for no other reason than racial hatred".
Referring to the length of sentence, he said: "In short, the law dictates that I must sentence you by reference to your age and maturity at the time of the crime. I cannot sentence you as the mature men you now are.
"In addition, I must sentence you in accordance with the practice in force before the coming into force of Schedule 21 of the Criminal Justice Act 2003 which now governs sentencing for more modern murders...
"It may be, therefore, that the resultant sentences are lower than some might expect, but the law as laid down by Parliament must be applied and I am constrained by it."