A dismissal of an employee in contravention of section 98 of the ERA 1996 (www.practicallaw.com/4-200-3207). For a dismissal to be fair it must be for one of the five potentially fair reasons in the ERA 1996 (conduct, capability, redundancy, breach of a statutory restriction or "some other substantial reason"), the employer must follow a fair procedure, and the decision to dismiss must be within the range of reasonable responses open to an employer in the circumstances.
For more information, see Practice note, Unfair dismissal: overview (www.practicallaw.com/2-375-8159).