Stuffy, crowded and poorly-lit workplaces are damaging the South- East's productivity.

A survey by energy company Npower said the most people believed a better atmosphere would increase their productivity.

The worst culprit was felt to be overcrowding followed by temperature.

One-in-four employees were dazzled or squinting at work and claimed better lighting would lead to better performance.

They also rated having good people and good conversation around them as crucial to creating a positive atmosphere.

Dr Glenn Wilson, reader in personality at the Institute of Psychiatry, University of London, and an expert in workplace stress, said:

"Atmosphere is a combination of our physical surroundings and how we interact with other people around us.

"Humans are pre-disposed to thrive in conditions that include a natural physical environment and a supportive social network.

"In work settings, contentment and productivity go hand in hand.

"While the benefits of a bright, well-heated and ventilated workplace are obvious, research also shows good intentions are helpful.

"Efforts to establish the right atmosphere for workers are a signal the employer cares about them.

This can be just as important as the physical measures themselves."

Npower director David Titterton said: "A dingy office can grind workers down."