When, if ever, it is appropriate for an employer to argue frustration of contract? For example, if an employee is given a prison sentence of 3 or more years for an offence that is no way connected with their employment, can an employer claim frustration rather than have to go through the statutory dismissal procedure using "some other substantial reason" as the potential reason for dismissal?

Case law confirms that a custodial sentence imposed on an employee is capable of frustrating the contract of employment but whether it does or not depends on the circumstances of the case with the length of the term to be served by the employee being a significant factor to be considered. Tribunals are often reluctant to find that a contract has been frustrated, as essentially the party asserting the frustration is avoiding their contractual obligations. Further, they also like to see the employee being given the opportunity to explain their position (somewhat difficult if the sentence is imposed and the employee can’t attend any disciplinary meetings).

Custodial sentences of three years