Backstabbing e-mails

London - 55% Leeds - 40% Cardiff - 39% Newcastle - 37% Manchester - 34% Birmingham - 34% Edinburgh - 32% Liverpool - 29%

With the fallout still surrounding civil servants' use of e-mails for political gain, office workers are acting as their own mini Machiavellis.

London is the biggest hotbed of electronic backstabbing with 55% using e-mails for political gain.

And Liverpool comes in as the least conspiratorial, with less than a third using e-mails to damage colleagues.

Discriminatory e-mails

Nearly 30% of those surveyed admitted to sending racist, sexist, pornographic or discriminatory e-mails whilst at work.

But the survey results also suggest that 80% of the nation's office workers believe that e-mail provides them with a "sense of protection" because everything is written and documented.

Offensive e-mails

London - 36% Manchester - 36% Leeds - 31% Newcastle - 28% Edinburgh - 28% Birmingham - 24% Cardiff - 20% Liverpool - 18%

Londoners and Mancunians were the worst offenders in the study, commissioned by internet filtering company SurfControl.

Offensive mail was sent by 36% of those questioned in both cities.

Liverpool was again the cleanest with only 18% using e-mail to offend.

NOP conducted 800 interviews with white-collar workers, 100 each in London, Edinburgh, Cardiff, Birmingham, Manchester, Leeds, Liverpool and Newcastle.

Ease of sending

SurfControl marketing director Martino Corbelli said the results of the survey were surprising.

He told BBC News Online: "Offensive e-mails seem to be taken as a bit of light-hearted fun."

Mr Corbelli said because of the ease of sending an e-mail, things were written which would never be put in a paper memo.

"If you wouldn't put it on company letterheaded notepaper, don't send it on e-mail."