By JAMES SLACK

Last updated at 12:48 29 December 2007

It's enough to make that old lag Norman Stanley Fletcher choke on his porridge ... prisoners have been banned from sharing "sexist" jokes.

Jail bosses say such quips could give the impression that women are "overly talkative" and "nagging."

There is even a danger it could turn convicts to a life of crime, they say - since some lawbreaking stems from men having a "negative" view of the opposite sex.

The reaction of the country's 81,000 prison inmates remains to be seen as they digest a list of jokes which are now officially off-limits.

It means that Fletch, played by Ronnie Barker in the classic television comedy Porridge, would certainly have been in trouble.

In a 1974 episode, while fantasising in his prison cell about having a night out, Fletch mused: "I could call up a couple of birds - those darlings who dance on Top of the Pops, what are they called? Pan's People. There's one special one - beautiful Babs ... I don't know what her name is."

Scroll down for more ...

The controversy stems from a lighthearted piece in Inside Time, the monthly newspaper of prisoners in which they swop jokes, concerns and stories. It was headlined "Victorian views perhaps?"

The list of jokes included: "Scientists have discovered a food that diminishes a woman's sex drive by 90 per cent. It's called a wedding cake." And "Why do men die before their wives? They want to."

But Steve Orchard, a head of operations at the Prison Service, was not amused - and he instructed Inside Time not to trade such "sexist" jokes again.

In a letter to the magazine's editors, the official, who works at Nottingham Prison, said he is not "fanatically 'PC' or lacking a sense of humour," but the jokes go too far.

He described some of the examples as "sexist in the extreme" and said they "should not, in my opinion, have been printed."

Mr Orchard insisted that some of the examples of gender prejudice would not have been acceptable if

their target had been people with disabilities or those from a black or ethnic minority background.

He added: "Similarly, I do not think they were acceptable in that they tended to reinforce negative and inaccurate stereotypical perceptions of women as unintelligent, overly talkative, nagging, deceptive and inferior."

He said some prisoners' offending behaviour stems from their inappropriate

attitude towards women. And that the Prison Service, despite some improvements, still remains probably overall "institutionally sexist in its staff culture," he added.

Mr Orchard said the magazine would be wise not to repeat its mistake - as good as an instruction, given his seniority.

So prisoners such as Fletch will have to find another way of brightening

their day, or stick to "knock-knock" gags.

There is some good news, however. An equally-PC edict recently said convicts should be called Mr, or by their first name, to create an atmosphere of decency and respect.

Mr Mackay, the senior warder at Slade Prison who tried his best to make Fletch's life a misery, would certainly not be amused by that.