The Working Time Regulations 1998 impose limits on workers' hours of work. Workers cannot lawfully be required to work more than an average of 48 hours a week.
However, a worker may agree to opt out of this weekly working time limit and work more than an average of 48 hours a week as long as he or she does so voluntarily and in writing.
The Working Time Regulations 1998 also give workers the right to a minimum daily rest period between each working day or shift, and to a minimum weekly rest period.