In summary:

• any dismissal of a zero hour contract employee is automatically unfair, if the principal reason is that s/he breached a contractual clause prohibiting him/her from working for another employer
• no qualifying period is required to bring such an unfair dismissal claim; and,
• it is also unlawful to submit a zero hour worker (note: worker not employee) to detriments if they work for another employer in breach of a clause prohibiting them from doing so.

The Exclusivity Terms in Zero Hour Contracts (Redress) Regulations 2015