Britain's most dangerous extremists will be locked up in isolated high-security prisons within prisons to prevent them from radicalising other inmates, the Government has announced.

The overhaul of the British prison system comes just days after it was revealed that hate preacher Anjem Choudary has been convicted of swearing allegiance to Islamic State and faces a decade behind bars, prompting concerns he could recruit other inmates to the terror group.

The new units will be built inside some of the UK's highest security jails and house only the most extreme inmates who promote terror and violence.