Changes to European law mean that workers who are taken ill or injured while on holiday should be paid sick pay for the days when they are ill.
They should also be allowed to retake their paid holiday at a later date.
Employers are allowed to make rules about notifying sickness whilst on holiday and about what rate of sick pay should be paid (as long as it is at least Statutory Sick Pay).
Remember that there are short deadlines for claims in the employment tribunal.
This issue is complicated. Speak to your rep if you want advice on asking your employer to pay sick pay or to reschedule holiday in these circumstances. It is best to act quickly.