Hundreds of criminals are to be allowed four days off prison work every year to celebrate Rastafarian festivals.
Prison governors have been issued with a list of holy days on which Rastafarian inmates must be excused their normal tasks.
On some they will be allowed to hold communal worship, and they may be provided with special food prepared by the prison kitchens.
Rastafarians, best known for their distinctive dreadlocks and their use of marijuana or 'holy herb' to produce 'spiritual' highs, believe the former King of Ethiopia, Haile Selassie, who died in 1975, is God.
The festivals that inmates will be allowed to observe include 'The Earthday/Birthday of His Imperial Majesty Haile Selassie I' on July 23. They will also be excluded from work on May 5 so they can celebrate the 'victorious return' of Selassie to his throne in Ethiopia in 1941 after 'the time of his exile in Britain'.
Rastafarian prisoners will be allowed the day off to celebrate the anniversary of the coronation of Selassie on November 2 and the Ethiopian Christmas - January 7.
The new Ministry of Justice guidelines, issued last month, state: 'The Prison Service is committed to ensuring prisoners from all religious faiths are given the opportunity and facilities to practise their religions.'
They add that relevant staff, including 'race equality officers/diversity officers', must be made aware of the new information about Rastafarian rights.
Prisons are told they must prepare specific foods if it is a requirement of a prisoner's religion. Rastafarianism was recognised as a religion by the Prison Service a few months ago after campaigns led by poet Benjamin Zephaniah. It has between 200,000 and 800,000 followers worldwide.
A Prison Service spokesman said it had been recognised as a religion following recommendations by the Prison and Probation Ombudsman.