Some call centres still resemble "satanic mills" despite moves to improve working conditions, a new report claims.

Research commissioned by the Health and Safety Executive found that many workers in the growing sector were treated like a "cog in a machine" with low wages, poor working conditions and highly repetitive duties.

Workers complained about being "tied" to their telephone, unable to take regular breaks and with little autonomy over their working day.

This confirmed previous surveys that showed some employees had to put up their hands for permission to use the toilet.

People working for telecom and IT firms showed the highest levels of depression.

But the survey of more than 1,000 call centre employees across the UK also found high levels of satisfaction among some staff.

Thursday January 08, 2004