Two high-profile Islamic terrorist prisoners who claimed their human rights were violated when they were segregated for extended periods have failed to persuade leading judges that their treatment was unlawful.
Three judges at the Court of Appeal in London dismissed challenges brought by Ricin plot conspirator Kamel Bourgass and "liquid bomber" Tanvir Hussain, who were alleged to have intimidated and bullied other inmates over matters of faith.
Prison authorities had considered it was necessary to separate them from other prisoners "for good order and discipline".
Both men denied accusations that they tried to influence and dictate the beliefs of other prisoners.
Today's ruling by Lord Justice Maurice Kay, Lord Justice Lloyd and Lord Justice Elias follows a decision against Bourgass and Hussain by a High Court judge in February 2011.
In that ruling Mr Justice Irwin said the procedures adopted to place them in, and keep them in, segregation, did not breach their common law rights, or their rights under Article 6 of the European Convention on Human Rights, to fair treatment.
Bourgass, 35, an Algerian, is serving 17 years for conspiracy to commit public nuisance by using poisons or explosives in relation to the 2002 Ricin terrorist plot.
He is also serving a life sentence for murdering Detective Constable Stephen Oake, 40, with a kitchen knife during his 2003 arrest at a flat in Manchester.
He injured four other officers during that attack and is serving sentences for attempted murder of two officers and wounding a third.
Hussain, 31, was one of three men convicted of a plot to launch suicide attacks on flights from Heathrow to America and Canada using liquid bombs made of hydrogen peroxide hidden in soft drink bottles.
He is serving life with a minimum tariff of 32 years.
Lord Justice Maurice Kay said that while detained at HMP Whitemoor in Cambridgeshire, Bourgass was segregated from March 10 2010 until April 22 and again from April 23 until October or November of that year.
On April 24 2010 Hussain was found to have carried out a "serious attack" on another prisoner at HMP Frankland in County Durham. He was subjected to segregation until October 2010.
The judge said Bourgass had previously been held at HMP Wakefield "where he had been considered to have influence over other prisoners and to be involved in bullying and intimidation".
He added: "Similar traits were observed following his transfer to HMP Whitemoor".
Bourgass was segregated on March 10 following an alleged bullying incident. After reviews by the Segregation Review Board (SRB) "it was considered that Bourgass had been responsible for an escalation of violence in the prison 'for faith-related reasons' and that his influence over other prisoners was a threat to good order and security".
In the case of Hussain, Lord Justice Maurice Kay said there had been a number of concerns following the April 2010 assault - the severity of the attack, the risk to other prisoners and the risk of reprisals.
There were also "intelligence reports suggesting that Hussain was involved in the conditioning of vulnerable prisoners who were susceptible to manipulation and that he preached extremist Islamic ideals through his cell window".
Dismissing the appeals, the judge said: "Prison or YOI (young offenders institutions) have the responsibility of maintaining good order and discipline in a complex and potentially combustible setting.
"They have to make urgent decisions about such matters as segregation based on their experience, expertise and judgment."
He said they are "acting in the interests of the security of the institution as a whole".
He added: "Sometimes they may have to make a decision which has an immediate restricting effect on the whole or a large part of the institution - for example, the immediate 'lockdown' of an entire wing on receipt of apparently credible information about a planned breakout.
"Such urgent matters are not susceptible to a judicialisation of the decision-making process."
In the cases of Bourgass and Hussain it would be "unrealistic" to require the initial decision to segregate to be taken by "an independent and impartial tribunal established by law".
The "need for action is often immediate", he said.
The judge said it seemed to him that reviews of the segregation imposed were "best entrusted to those with the necessary experience and expertise as an exercise of collective, professional discretion, with built-in safeguards".
He added: "Amenability to judicial review is appropriate protection."
Article 6 "was not engaged at the stages of the Governor's decision or the SRBs".
He said: "In my judgment, the decision-making processes within the prison and the role of the SRB provide a satisfactory framework for professional and evaluative judgments with the safeguard of judicial review."