Ron Adams, vice-chairman of the Prison Officers' Association, said: "They are absolutely livid. They all wanted to go home but we managed to stop them." They refused to leave the chapel until they had received guarantees about they safety.
The staff had expected no more than three officers to be charged after a year-long police inquiry into allegations by about 50 inmates, he said. The officers ended their sit-in and returned to work last night after an offer from the governor, Stephen Moore, which union leaders said was aimed at improving their safety and preventing inmates making unfounded allegations.
The officers called for training in control and restraint when dealing with violent prisoners and counselling from care teams for suspended officers and other staff "distressed" by the developments. They also demanded a management presence on prison landings. All 25 of the accused officers have been suspended.
Martin Narey, director- general of the Prison Service, said: "I am committed to dealing fairly, openly and humanely with prisoners. If Prison Service staff abuse their position of authority through violence then there is no place for them in the service."
There were growing fears of unrest among the 1,000 inmates at the jail, who had been following developments on in-cell televisions. When they were prevented from leaving, they banged angrily on their cell doors and visits from friends and relatives - some of whom had travelled from the north of England - were cancelled because of the staff protests.
The Prison Service said yesterday that the jail's D-wing was being closed for early refurbishment and up to 40 prisoners a day would be transferred to other establishments.
The crisis at Wormwood Scrubs, once the Prison Service's flagship jail, was first highlighted two years ago by the Chief Inspector of Prisons, Sir David Ramsbotham, who said it was "dead in the water". In a further report, due to be published in three weeks, he will call for the prison to be closed or privatised.
The criminal charges follow a police investigation into allegations of assaults between January 1997 and May 1998, mostly at a segregation unit at the prison.
A separate police investigation into further allegations of assaults between 1991 and 1996 and since May 1998 has not yet been completed.
Daniel Machover, of the London solicitors Hickman & Rose, which represents many of the alleged victims, has called for a public inquiry into the whole Wormwood Scrubs affair.
The officers' association supported the idea, saying that such an inquiry would highlight management failings and exonerate its members.Reuse content