Union bosses at HMP Wymott, near Leyland, which is home to 1,000 prisoners, many of whom are convicted sex offenders and violent criminals, say staff are being marked down in assessments if they can't prove they have treated inmates decently.

In addition to the Prison Service's national "decency agenda," management at the jail, which is run by governor Jayne Blake, say inmates must be addressed as "Mr", followed by their surname at all times.

One prison officer who was assaulted by a violent inmate was even told the charge would be dropped unless he called his attacker "Mr" throughout the hearing, according to Ron Crosby of the Prison Officers' Association (POA).

It comes a fortnight after the Evening Post revealed Lancashire inmates have access to a catalogue of luxury goods which they can use to make their cells feel more like home.

In a joint letter to the Lancashire Evening Post, Wymott POA chairman Ron Crosby and deputy chairman Howie Probert said the test of the decency agenda is: "Would we as members of the prison service like our children to be treated in the same manner as prison staff treat prisoners today?"

Mr Probert said: "All serving prison staff buy into this agenda and treat prisoners decently and with humanity, even under exceptionally difficult circumstances."

Chorley MP Lindsay Hoyle, whose constituency includes the category C jail, pledged to raise the issue with the Home Office.He added: "It is an absolute disgrace. It is as though the inmates have taken over the asylum.

"We ought to remember it is the prisoners that have done wrong, not the prison officers."

>> Vote in our latest web poll