Employers are unwittingly contributing to record levels of online Christmas shopping by allowing employees to browse for gifts during working hours, a recent poll has found.

The survey of 2,700 IT administrators in the US and UK, conducted by content filtering firm SurfControl, indicated that approximately three out of five UK firms fail to restrict employees' access to online shopping sites.

Most simply block access to sexually explicit websites (97 per cent) and web-based email (45 per cent), such as Yahoo and Hotmail.

Analyst IDC estimates that about 30 to 40 per cent of employees' internet use is not business-related, even before the distractions of the holidays begin.

"Every year, non-business internet usage increases by 10 to 15 per cent," said Brian Burke, an IDC security analyst.

"As business use of the internet grows, so does 'incidental' use at the office, such as music downloads, sports and shopping."

Susan Getgood, SurfControl's senior vice president of marketing, said: "The results suggest that companies are more tolerant about online shopping and focus more on monitoring abusers.

"It appears many firms are trusting employees to use good judgement about how and when they use the internet at work, as long as it doesn't become a productivity issue."