British office workers spend a third of their working day surfing the internet, according to a new survey.

Holiday firm Thomas Cook found that UK staff wasted two-and-a-half hours a day, a staggering 75 days of the working year, conducting personal business on the internet.

The biggest drains on work time were email and instant messaging, according to the survey, with one in 20 spending two hours a day chatting to their pals over the internet.

However, companies are becoming more aware of employees' online habits. The survey found that 22 per cent of workers have been caught out by their boss, and two per cent have been sacked for skiving online at work.

Over a third of workers admitted that they would get more done at work if they were banned from using the internet.

"Most office jobs involve around 99 per cent of work being done on a computer, so it's easy to see how people get away with surfing the internet so much. But this must be costing companies thousands," said Carol Dray, director of Thomascook.com.

"While most companies don't mind employees doing some personal business during the day, it can definitely be taken too far."

More than one in 20 British employees has the nerve to spend an hour a day looking for other job vacancies.

And almost three-quarters justify their surfing, believing that their 'hard work' for the company means they deserve to browse the net 'from time to time'.

Almost 40 per cent of respondents complete most of their personal tasks at work, and a quarter of Brits indicated that they have no use for their home PC.

More than 2,000 office workers took part in the survey.