Over half of UK employees are suffering from the summer blues and some are even considering quitting their jobs as a result.

This is the conclusion of a new survey by the Training and Development Agency for Schools (TDA), which found that 58 per cent of UK workers experience reverse Seasonal Affective Disorder (SAD) during the summer months.

Some 20 per cent of employees polled said they spend their summer staring out of the office window, while eight per cent said they were more likely to call in sick at this time of year.

And seven per cent of workers said they felt so de-motivated at work during the summer that they started looking for another job.

Offering staff extra days off is one way to keep them happy and motivated, according to John Challenger, the chief executive of the US outplacement firm Challenger, Gray & Christmas.

He told the Associated Press that there had been a big increase in the number of companies offering Summer Fridays as a perk to maintain motivation levels among workers.