With Christmas shopping becoming more popular than ever, more employees are using office hours to shop for online bargains.

With thousands of staff-hours being lost as workers visit online stores, employers are having to come up with strategies to stop staff spending too much time surfing the internet for that elusive festive gift.

UK consumers are expected to spend £7bn online this Christmas and Monday was the busiest day of the year when about £14m was spent online between 1pm and 2pm. Overall online sales this week are expected to top £1bn.

But while online retail outlets are reaping the rewards, company bosses are left panicking their staff might spend more time surfing amazon.co.uk and play.com than delivering results.

With staff access to the web an essential tool for companies, and with hours of work increasing, the temptation for employees to shop at work is huge. Also, the rising trend of home working is blurring the line between personal and office use.

An international survey commissioned by Cisco systems, the internet equipment maker, found online shopping was the leading personal use of work laptops. About two in every five employees who used their computer for personal use said they were using the internet to buy goods and services.

Employment Law Advisory Services, a body which advises about 2,000 British businesses, calculated online shopping in the run-up to Christmas could nationally cost companies more than £7bn in wasted work hours.

Dan Chapman, employment lawyer at city firm Leathes Prior, said Norwich companies were mainly concerned about staff productivity and computers getting viruses.

He said sackings were rare and usually only for excessive misuse, but online shopping could lead to written warnings and disciplinary hearings.

Mr Chapman said: “It's a new area of employment law. The use or misuse of internet at work is a hot topic and obviously Christmas is exacerbating the problem.

“About five years ago we were seeing a few cases of abuse of the internet whereas nowadays we are seeing a lot more internet-related issues, and Christmas is a manic time with online shopping, so we expect to see a drastic increase in issues.

“At the end of the day, internet abuse can constitute gross misconduct.”

He said one Norwich employee was dismissed for spending six hours a week of work time surfing the internet for personal use. A tribunal decided it was the equivalent of not coming to work for six hours a week and so found for the employer.

Mr Chapman said: “The employee was not supposed to access the internet during work time, so it was seen as definitely gross misconduct.”

There is no specific legislation which governs internet use but what it boils down to is whether an employer has an internet policy in place and whether the employee is breaching it.

As long as a company laid down acceptable rules and communicated them effectively it had a solid legal basis to take disciplinary measures, Mr Chapman warned.

For businesses without a policy in place it was a grey area as to whether an employee was breaching their contract, he added.

Mr Chapman said: “There is no law that says you can't do online shopping in work hours between 9am and 6pm.

“I advised an employer once who did not have an internet policy and was threatening to discipline someone who did, but the employee maintained it was the same as the smokers who took a break and so it became arguable as it whether there was a breach of contract.

“A lot of employers turn a blind eye to it and then if you pick on one employee they can say it's unfair as everyone is doing it. It is the duty of employers to treat employees in a fair and even-handed manner.”

Employees are often not aware they are breaching their company policy by shopping online nor are they aware how much time they spend on the internet. Websites are now geared to keeping shoppers online for as long as possible so even an occasional glance can turn into half an hour browsing.

Mr Chapman said: “It's not as bad a stealing from your employer, but half an hour personal surfing of the net is the same as turning up to work half an hour late every day.”

He said employees might mitigate in a tribunal saying that they couldn't find time during office hours to shop.

“An employee in these circumstances should say to his or employer 'I can't get to the shops and therefore would you mind if I spent the odd minute doing shopping here?'

“The more people purchase online the greater the risk of picking up a virus. There is also a contractual issue with an e-mail address. Employees may not realise that by buying something online they're creating a contract between employers and the retailer and the employer could be liable if the employee doesn't pay up.

“The advice I would give employees is to only access the internet in accordance with what your policy says and if you want to access the internet during the day, ask your employer if you can.”