Police are to be banned from using the word 'yob' in case they offend delinquents, it has emerged.
Scotland Yard chiefs have told staff to find a more polite way of referring to troublemakers.
The extraordinary edict - described by critics as 'pathetic' - has the backing of Met Commissioner Sir Ian Blair, often referred to as Britain's most politically-correct policeman.
It applies to all reports submitted by officers to the Metropolitan Police Authority, which oversees the running of the capital's force.
The ban was imposed after the word 'yobs' cropped up in a report presented to members of the authority last week.
The document on Safer Neighbourhoods by Chief Superintendent Steve Bloomfield stated that Scotland Yard was "proactively tackling gangs and yobs across London".
Objecting to the phrase, Cindy Butts, the police authority's deputy chairman, told Sir Ian that the term was 'alienating'.
She added: "I have a problem with the language of 'yobs'. It sort of sets up and defines too much a 'self' and 'other'."
Assistant Commissioner Tim Godwin agreed, saying: "I'm sorry about that. We won't use that again."
Afterwards Mr Godwin confirmed that the use of 'yobs' would not be repeated in Met documentation and was now officially banned.
He claimed the word could be taken as a slur on groups of lawabiding youngsters.
"It can reflect on groups of youths who congregate, rather than those who carry out criminal activity," he said. "We have to be careful because of the need to engage with young people."
Senior Met sources called the decision 'pathetic', pointing out that Sir Ian used the term himself when he broadcast on BBC1 last November.
Giving the BBC's annual Dimbleby lecture Sir Ian said: "Society is demanding answers and actions to deal with feral children, hoodies and yobs."
Richard Barnes, a Tory member of the Met police authority, hit out at the initiative.
He said: "We have to use words which are in common parlance, as long as they are not insulting.
"When we hear the word 'yobs' we all know what we're talking about."
Politicians are unlikely to follow the Met's lead in extending the boundaries of politically correctness-MPs on all sides frequently use the term 'yob', including Tony Blair who referred to yobs in the Commons in 2004.
The word is thought to have originated in mid-19th century London as a slang term for an uncouth blue collar individual or thug.
It derives from a back-slang reading of the word 'boy'. It was reversed to become 'yob'.
As the word spread into more general English usage, it was often extended to 'yobbo' and is now defined as a 'teenage hooligan or lout'