Some of the country's most dangerous and subversive extremists have been moved to a "prison within a prison" to help tackle radicalisation behind bars.
The inmates are now housed in a separate centre within HMP Frankland in Durham to stop them influencing fellow prisoners.
The move will also see two other separation centres created within high-security jails, with the three centres combined holding up to 28 of the most radicalised offenders.
They will see inmates suspected of planning terrorism or posing a risk to national security face being moved away from the mainstream prison population.
Lee Rigby murderer Michael Adebolajo and extremist preacher Anjem Choudary could be among them.
Those who spread views that might incite others to commit terrorist offences, or whose extremist views are purposely undermining good order and security in jails, could also be shifted to one of the facilities.
More than 4,500 frontline prison officers have received the latest specialist counter-extremism training to identify and challenge extremist views, with new recruits to the prison service now receiving the training as standard.
Prisons minister Sam Gyimah said: "Extremism must be defeated wherever it is found.
The most dangerous and subversive offenders are now being separated from those they seek to influence and convert, an absolutely crucial element of our wider strategy to tackle extremism in prisons and ensure the safety of the wider public."
The Ministry of Justice declined to comment on which prisoners were being moved for security reasons.
Last month, Adebolajo, who killed Fusilier Rigby outside the Royal Artillery Barracks in Woolwich, south east London, in May 2013, was said to be "brainwashing" fellow inmates in prison.
Adebolajo, who was being held at HMP Frankland ahead of the separation centre being created, was described as spending "most of his waking hours preaching his distorted form of Islam to anyone who will listen", according to the Daily Mirror.
The new centre at HMP Frankland was one of the central recommendations of a landmark review which warned that Islamist extremism is a growing problem within jails.
The assessment found evidence of offenders advocating support for the so-called Islamic State and ''charismatic'' prisoners acting as ''self-styled emirs'' to radicalise other inmates.
It also suggested that ''cultural sensitivity'' among staff towards Muslim prisoners could ''inhibit the effective confrontation of extremist views''.
Figures indicate authorities are managing more than 1,000 inmates who have been identified as extremist or vulnerable to extremism at any one time.
The new centres will be used to target all forms of extremism in jails, including Islamist and extreme far-right ideologies.
They will be completely separate from the main wings of the three establishments where they are located, and staffed by personnel from the existing high-security estate.
Decisions on which prisoners are placed in the units will be taken by specialist senior staff.
Convicts serving sentences for non-terror related offences could also be moved to the centres if they show signs of serious extremism behind bars.
In April, the Government launched a 100-strong team of counter-terrorism experts to tackle ''poisonous'' extremism in jails.