BT is encouraging office workers to spend more time outdoors, after a survey revealed that nearly a quarter of urban workers see fewer than 20 minutes of natural sunlight during the working day.

The research found that many employees are so chained to their desks that they see the sun for less than an hour a day.

BT said that, with the growth of remote and mobile working technology, being at a desk and being productive are no longer mutually exclusive.

"Out of the office no longer means 'out of touch' and workers can stay just as productive when not chained to their desks," said Dave Hughes, director of wireless broadband at BT Retail.

"Wi-Fi enabled devices and widely available hotspots provide the tools to support remote working. Let's just hope that the British weather plays along this summer."

Four out of five respondents described themselves as 'unmotivated' knowing that they will be stuck indoors while the sun is shining, and 65 per cent even claimed that the lack of exposure to sunlight made them 'depressed'.

Stephen Alambritis, head of public affairs at the Federation of Small Businesses, agreed with the findings.

"Lack of sunshine or outdoors activity has an enormous effect on morale, and productivity is likely to drop in tandem," he said.

"With a wide variety of internet access options available to office workers, and more bosses approving remote working, there has never been a better [time] for workers stuck at their desks to get some productive time in the sun."

BT is advising those who do head outside to be aware of physical and virtual security by finding a sensible and safe location to work in, and using proper security software to access work systems and protect sensitive information.