There is a series of soup adverts for television that is very amusing, but also a disturbing sign of the times. We see an employee in the office kitchenette fixing her underwear, doing a dance and kissing a colleague. It's supposed to be hilarious because she obviously doesn't know she's been caught on closed circuit television (CCTV) doing something really embarrassing.

In real life, it's not funny at all for employees who are under surveillance at work. It may all be very cliched, but Big Brother is watching.

Visual and audio recording devices can be fitted practically anywhere, and they may not always be visible. Don't look now, but you know that smoke alarm on the ceiling or the lever arch file on the shelf? - there could very well be a camera hidden there. And that pen you were given last week - it's fitted with a recording device. Get used to it. You'll probably be under surveillance for the rest of your working life.

There is a great divide between employees and their employers about the installation of surveillance equipment.

Mr Donncha O'Connell, director of the Irish Council for Civil Liberties (ICCL), believes the problem in this jurisdiction is that incursions on privacy take place in the absence of a legal or regulatory framework that values privacy. "Effectively, we have no law on privacy in Ireland, apart from a constitutional guarantee, the precise parameters of which are unclear. The Law Reform Commission has called for a law on privacy, and we in ICCL would support that call on the basis that technological developments are now so rapid as to constitute a very serious threat to the attainment of even a minimal level of privacy."

According to Mr O'Connell, in the context of the workplace it is increasingly common for workers to be subjected to electronic spying mechanisms. These, he says, are usually justified by employers as vital security measures that benefit employees' as much as employers' interests.

This may be the case in situations where employees are aware that surveillance is being used and have consented to its use. However, Mr O'Connell believes it is increasingly common for technology to be used without informing employees, and "such practice is objectionable for a number of reasons".

Mr John Douglas, a national official with Mandate trade union, specialises in industrial relations. He says that there have been a number of court cases regarding invasion of privacy where staff have found hidden cameras.

Surveillance has increased over the last four to five years, he says, especially in cash businesses where a camera is openly on display. However, when a camera is hidden, he says, there are overtones of dishonesty.

"We wouldn't have a problem per se with cameras, once they were there for health and safety reasons." Cameras installed "as a matter of routine" are where the problems arise. "At the least it's distasteful and at the worst it's an invasion of privacy."

The key issue is having an understanding between staff and employers, so there is an awareness of surveillance. "Consent," Mr Douglas says, "is the key issue". Covert surveillance paints all employees with the same brush, he says. It can also have other "sinister overtones". Mandate says it has been told of the practice in some anti-union companies of monitoring phone calls and conversations in canteens. "It's a question of civil liberties; it's a question of Big Brother watching you," says Mr Douglas.

Mr Charlie Donaghy, owner of Surveillance Systems, has seen a "massive increase" in the demand for surveillance since he set up shop in 1990. "At the same time cost has come way down, making it more affordable to customers."

There are various forms of surveillance, apart from plain old CCTV. Covert cameras are used mainly for theft in work areas and timekeeping, he says. Alarms can be monitored by checking times of entry and exit to see if staff are coming in out of hours. E-mails and computer use are also monitored.

CCTV, though, is "absolutely necessary" for warehouses. "Seventy per cent of all theft is through internal staff" as opposed to shoplifters or outsiders, says Mr Donaghy.

There are numerous locations where covert cameras can be hidden - in smoke alarms, movement detectors, briefcases, arch lever files. In his experience these hidden cameras account for 30 per cent of CCTV installations for any one company.

CCTV is perfect for a business wanting to monitor its many outlets at any given time, he says. Mr Donaghy knows of one businessman who has 150 premises in the UK, all with CCTV connected to a phone line, so he can access any one of them at any time.

CCTVs can record up to a month of visual and audio, he says, but some companies opt for just audio recording devices, which will either transmit or record. "You can do it with double sockets and pens." The surge in demand for surveillance equipment has to do with the state of the economy. "When there's a boom, people spend money on surveillance."

That's not to say the market disappears when tougher times hit the economy. "When there's a recession, people are more prone to theft."

White-collar theft occurs, Mr Donaghy says, when the cost of living increases and people steal to keep up their lifestyles. He thinks these are the people who should be worrying about being under surveillance.

"Honest staff don't complain about surveillance; an honest person wouldn't mind," says Donaghy. "Honest people have nothing to worry about. It's the guilty person who minds." Mr Pat Delaney, director of the Small Firms Association, is pro-surveillance. He says we are living in an environment that has changed - one in which employees need to be protected from the public and their colleagues.

"The duty of care aspect is paramount," he says. Cameras can be used as an "evidential record if sexual harassment or bullying are taking place", he says. These are areas in which a growing number of complaints are being received. Mr Delaney claims it stops bullying.

"Cameras are never used to monitor performance," he insists. Monitoring of performance is a management function.

Hidden cameras, Mr Delaney explains, are mainly used at cashpoints or where an employer has view of leakage taking place. But, he says, "a line has to be drawn at entrapment." It is this fine line that causes a rift in industrial relations and concerns over privacy.