Nearly a quarter of employees could be missing out on their full holiday entitlement if companies fail to increase allowances in accordance with new guidelines.

That is according to research commissioned by Croner, which revealed that 21 per cent of workers in the UK were entitled to less than 27 days off including bank holidays.

From today, the statutory minimum holiday allowance will be increased from 24 to 28 days.

Commenting on the importance of holiday, Gillian Dowling, employment technical consultant at Croner, said: "Money and holidays are often the key motivators when searching for a job and are an essential part of an employment contract. At the moment it seems not everyone is aware of their rights."

Ms Dowling said that companies face "employment law risks" if they fail to give staff the correct holiday entitlement.

Croner advised employers that the Working Time Regulations, which outline the statutory minimum holiday allowance apply to casual staff in addition to permanent employees.