The UK's Information Commissioner's Office (ICO) says employers must make their staff aware of the nature, extent and reasons for monitoring.

It comes as new research commissioned by the ICO reveals that nearly one in five people (19%) believe they have been monitored by an employer.

Monitoring can include tracking calls, messages and keystrokes, taking screenshots, webcam footage or audio recordings, or using specialist monitoring software to track activity.

However, the ICO has today published new guidance in which it says any monitoring must be necessary, proportionate and respect the rights and freedoms of workers.

Emily Keaney, Deputy Commissioner of the ICO, insisted the watchdog will "take action if we believe people's privacy is being threatened".

"Our research shows that monitoring at work is a real cause for concern, particularly with the rise of flexible working - nobody wants to feel like their privacy is at risk, especially in their own home," she said.

"If not conducted lawfully, monitoring can have a negative impact on an employee's wellbeing and worsen the power dynamics that already exist in the workplace.

"We want people to be aware of their rights under data protection law and empower them to both identify and challenge intrusive practices at work."

The new guidance from the ICO - the UK's independent regulator for data protection and information rights laws - says employees must tell staff about any workplace monitoring and deliver it in a way that is "easy to understand".

Monitoring must also have a "clearly defined purpose" and use the "least intrusive means" to achieve it, according to the new guidance.

The ICO says any data collected should be processed in line with data protection laws, and should be made available to staff through a Subject Access Request (SAR).

"We are urging all organisations to consider both their legal obligations and their workers' rights before any monitoring is implemented," Ms Keaney said.

"While data protection law does not prevent monitoring, our guidance is clear that it must be necessary, proportionate and respect the rights and freedoms of workers."

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As part of the new guidance, the ICO has commissioned a new survey which shows that 23% of younger staff - those aged between 18 and 24 - believe they have been monitored at work.

It is higher (25%) for those aged between 25 and 34, while only 11% of older workers - those aged over 55 - believe they have been monitored.

Of those who took part in the survey of around 1,000 UK adults, 70% said they would find it intrusive to be monitored by an employer.

Around a fifth (21%) said they would not find it intrusive to be monitored by an employer in any way.

Older workers (76%) were also more likely to find workplace monitoring intrusive, compared to younger people (60%), while men (22%) were more likely to feel comfortable with monitoring compared to women (16%).

The guidance from the ICO comes following the increase in employees working from home since the COVID pandemic.

In May, figures from the Office for National Statistics (ONS) revealed that more than eight out of 10 people who worked from home during the pandemic planned to carry on hybrid working in the future.

The proportion of people planning to work primarily from home also rose from 30% in April 2021 to 42% in February 2022.