Ever get the feeling you're being watched at work? If you've given your boss a good reason to snoop you probably are. But before you become too paranoid read on to find out what rights you have.

Is my employer allowed to check up on me?

Sorry, the answer is yes. The legal ways you can be monitored at work include:

• Opening your post or emails, or using automated software to check emails
• Checking your internet history
• Checking logs of phone calls made, or recording calls
• Recording footage on CCTV cameras
• Requesting information from credit reference agencies

Should they tell me first?

"Employers have a duty to tell you if they are monitoring staff," says TUC general secretary Brendan Barber. "Covert monitoring is only permitted in very limited cases, e.g. if an employer suspects someone is committing a criminal offence."

"Individual companies set their own policies, but they must comply with data protection laws," says Brendan. "For example, employers must tell you about the types of information they hold about you and what they intend to do with it. These rules apply to everyone across the UK."

Many workplaces provide a written policy, including rules about use of email and the internet. This will usually form part of your contract of employment, so breaking it could land you in trouble. This is what happened to Claire, 25, when she spent too long online at her city council job.

"We were allowed up to two hours online a day, but I clocked up five," she says. "The IT department emailed my line managers asking them to give me a warning. I felt really awkward as it happened in my first month." Her advice? "Check your employer's policy before going online at work."

Do they have to ask permission before monitoring me?

No, so long as they take reasonable steps to let you know, you're using equipment provided for your job and they're monitoring you for one of the following reasons:

• Establishing facts relevant to the business
• Checking the quality of your work or if procedures are being followed
• Preventing or detecting crime
• Checking for unauthorised use, such as using the internet for non-work purposes
• Making sure systems are operating effectively
• Checking communications you receive are relevant to the business
• Checking (but not recording) calls to confidential helplines
• Issues of national security

I'm worried about monitoring at my workplace, who can I talk to?

Try having a chat to your employer, or ask your trade union if you belong to one. Citizens Advice Bureau (CAB) has guides to resolving disputes at work for England, Scotland and Wales, or dealing with grievances, dismissal and disciplinary action if you're in Northern Ireland.

If you're worried your employer's monitoring practices are breaking the law or you just want some advice about them, you can talk to someone at the Information Commissioner's Office (ICO) and CAB.

Can employers test for drugs?

The legal position for drug testing at work is complicated but it's acknowledged that employers have a justifiable interest in employees' drug use in certain circumstances. These include employees using drugs or alcohol in the workplace, or if drug or alcohol use is affecting your performance or safety at work. But a drug test shouldn't be imposed on you, and should only be introduced after a consultation.

What about my privacy?

You have a right to privacy, but because work computers, email accounts and phones aren't your private property you have to be careful about how you use them.

One of Claire's colleagues was reprimanded after her boss checked her emails and saw some remarks insulting a co-worker. "She hadn't realised that deleted items go into a trash folder, rather than being deleted forever," says Claire.

Even on a private computer, you still need to be careful, as 20-year-old Paul discovered after joining a Facebook group criticising the high street retailer he worked for. "When I was called into the manager's office I had no idea what it was for," he says. "The store manager had looked through these groups and spotted me. I received a warning and left the group after that. My advice is not to say anything online that you wouldn't say to your boss's face."

And think twice before you tweet anything detrimental. In March 2009, 22-year-old American Connor Riley made a post on Twitter about a job offer from Cisco, saying she would hate the work. She thought only her friends could read it, but Cisco saw it and withdrew the offer.

Updated: 18/02/2013

By Anne Wollenberg