Attacks on prison staff have soared to their highest level for more than two decades, with some 10,000 assaults recorded in a year.

The number of incidents in the 12 months to June shot up 30% to 10,281, compared with 7,907 a year earlier.

This is the highest level in any 12-month period on record since 2003, PA news agency analysis of Ministry of Justice (MoJ) figures published on Thursday shows.

Campaigners branded the figures “shocking” as the prisons minister warned the rising violence behind bars against “hardworking staff” had reached “endemic levels” and illustrated the scale of the “crisis” in jails inherited by the Government.

In the latest year, nearly 1,000 of the attacks were classed as “serious”, which includes incidents needing medical treatment or a trip to hospital, or injuries such as fractures, burns, extensive bruising, black eyes, broken noses and teeth, cuts, bites, temporary or permanent blindness and sexual assault.

The rate of serious assaults on staff rose year-on-year by 24% to 11 per 1,000 prisoners (974, up from 746).

Pia Sinha, chief executive of the Prison Reform Trust, said: “These shocking figures underline the very human consequences of the severe pressures the prison system is under.”

Prisons minister Lord Timpson, said: “These statistics yet again illustrate the scale of the prison crisis this Government inherited and how prisons are failing their basic function to cut crime.

“Attacks on our hardworking staff have reached endemic levels and the rate of self-harm has peaked at a depressing high – both indications of the system’s failure to rehabilitate.

“This new Government has already taken urgent action to save the prison system from the point of collapse and we will now make the reforms necessary so that prisons are safer and make better citizens, not better criminals.”