(1) The Employment Rights Act 1996 is amended as follows.

(2) After section 27 insert -

"PART 2A ZERO HOURS WORKERS

"27A Exclusivity terms unenforceable in zero hours contracts

(1) In this section "zero hours contract" means a contract of employment or other worker's contract under which -

(a) the undertaking to do or perform work or services is an undertaking to do so conditionally on the employer making work or services available to the worker, and

(b) there is no certainty that any such work or services will be made available to the worker.

(2) For this purpose, an employer makes work or services available to a worker if the employer requests or requires the worker to do the work or perform the services.

(3) 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.

(4) Subsection (3) is to be disregarded for the purposes of determining any question whether a contract is a contract of employment or other worker's contract.