Flexible working is a term that is used to describe changes in working hours or patterns that allow an employee to more easily combine work with family or other commitments.
It is also being more widely used to describe changes made by employers to put their workers on short time or part-time hours if there is a shortage of work.
Any change to working hours will need the ageement of both the employer and employee as it will involve a temporary or permanent change to the contract of employment. This is important as if a permanent change is agreed there might not be any agreement about a return to the previous hours or terms if the arrangement is not satisfactory for one of the parties.
Changes to the contract will also usually involve a change in pay to reflect reduced hours.
Any employee can try and negotiate a change in hours with their employer - see:
There have been a number of rights to request flexible working created in law in the last few years. In general they are rights to request flexible working hours rather than a right to have such working hours. The rights will apply in set situations.
The links below will give you more information on the situations and rights.