It is a situation which can arise in many homes which employ domestic/ household staff – you the employer take your holidays at fixed times of the year and you require your staff to look after the house while you are away.
So, are you able to control when your domestic staff take their annual leave?
Well, if you already know your dates before your employee commences employment with you, dates in which they cannot take their annual leave can be stipulated in their contract of employment.
If, however, what if this is not written into the contract, but the employee has been with you for some years and you have consistently asked them not to take holidays during a set period to which they have agreed?
You can then say that this is implied into the terms and conditions through custom and practice, in other words, through consent it has become the norm and thence effectively becomes a working practice.
It must of course be recognised that all such restrictions only apply during a defined period of time and that the employee must be allowed to take their full leave during the year in which it was accrued.