This is not uncommon and it is known as ‘moonlighting’. It is actually perfectly legal for an employer to have a clause requiring their consent before you take up other employment, even if it is done entirely in your own time. There are various reasons for this:
· Working elsewhere could affect your performance in the main job, if you work too many hours and get tired or have to think about other issues in other jobs
· Under law you are only allowed to work a maximum of an average of 48 hours per week and if you do other work then the main employer could be in breach of these Regulations when they include their work in this calculation
· Again, legally you are required to have minimum rest periods between work, such as 11 hours between finishing and starting and if you do other work the main employer could be acting in breach by requiring you to work at specific times which encroach on this.
So as you can see it is not just a matter of what you do in your own time is your own problem. Undertaking other work will also have implications on the main employer and they can make it a condition of the contract that you seek their consent before you undertake additional work. This is usually what happens, rather than them issuing a blanket prohibition on you working elsewhere, which they can also do. Whilst no one can stop you to undertake other work, the employer who has this clause in the contract can take further action, such as capability However, if there are no foreseen issues, there is no reason why they should unreasonably withhold their consent.
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