In reply to Parthian Climbing:
> Our zero-hour contract employees have the freedom to work elsewhere, with the exception of a direct competitor. This may cause a conflict of interest and have a detrimental effect to our business.
Actually, your zero-hour contract employees have the *right* to work elsewhere, *including* for a direct competitor, because in making them zero-hours employees, you give up any right to dictate such conditions to them. And you gave up that right voluntarily when you told them that you were under no obligation to give them work. It's the law.
The potential effects of them working for a competitor is entirely your headache, not theirs: put simply, you're creating the problem, not being the victim of it. If you used different contracts, with at least some guaranteed hours, you could dictate to them. But you don't, so you can't.
Section 27A (the amendment in question), subsection 3 states:
Any provision of a zero hours contract which—
(a) prohibits the worker from doing work or performing services under another contract or under any other arrangement, or
(b) prohibits the worker from doing so without the employer’s consent,
is unenforceable against the worker.
So, either of two things are happening here:
1) Your HR company doesn't know this and are leaving you open to action. You might want to have another word with them.
2) Either you, the HR company - or both - know that despite exclusivity clauses being illegal, currently there are no enforcement provisions, which means that vulnerable workers have to take private action to protect themselves, inevitably leading to their contracts being withdrawn. So either way, they lose.
Which is worse.