A 51-year-old man phoned the police and told them he had a knife and was going to stab somebody.

Blackburn magistrates heard that Paul Mahon had made similar phone calls previously and had only been released from prison a week before the latest incident.

Mahon, of no fixed address, pleaded guilty to possessing an offensive weapon. He was jailed for 120 days.

Alex Mann, prosecuting, said alcohol seemed to play a part in Mahon repeating the same offence.

“On this occasion he rang from a call box and when the armed response unit arrived, as they must, they found a knife in his sock,” said Mrs Mann.

“On other occasions they have found two knives and while nobody has been harmed, each time he phones, the police have to take it seriously.”

She told the court that Mahon had already been jailed twice this year for similar offences and had only been released from prison a week before the latest call.

Jonathan Taylor, defending, said getting drunk, going to the phone box and making threats had become a habit for his client.

“He has virtually no recollection of any of the phone calls,” said Mr Taylor.

“He drinks too much and doesn’t know why he does what he does.

“Clearly it is a cry for help but until somebody gets hold of his alcohol problem the cycle of offending will just continue.”