According to a report, more than a million workers will fail to take all their holiday leave this year.
It found workers will give up a total of 6.2 million days of annual leave, with the average of unused holiday standing at five days, the Daily Mail reported.
The research, commissioned by price comparison website TravelSupermarket, found that more than one in four of those who will shun their remaining holiday entitlement (28 per cent) will do so due to pressures at work.
Nine per cent of the 2,020 people polled also said they would feel guilty about taking the leave because their work would have to be taken care of by their colleagues.
A further three per cent said they would be concerned about how taking time off would look to their employer, while the same proportion said they didn't want to miss out on anything interesting or beneficial at work in the time they would be away.