Rights of casual workers between assignments

Whether casual workers have any rights between assignments will depend on the contractual arrangements between the parties — worked out primarily from the contract documentation, but also from the surrounding context — and on whether these arrangements give rise to mutuality of obligation in between each work assignment. The key question is: is there a continuing obligation to offer some work and to do some work if offered? This is often described in the cases as an “umbrella contract”.

In Carmichael v National Power [2000] IRLR 43, workers engaged as guides to a power station were employed “on a casual, as required basis”. They brought a tribunal claim asking for a statement of employment terms, which at the time, required 13 weeks of continuous service. While working on each individual assignment, there was clearly mutuality of obligation between the guides and the power station. However, since they worked only intermittently “as required”, the House of Lords (now Supreme Court) decided that in between assignments, there was no mutuality of obligation on the power station to offer work or on the guides to accept it. As a result, there could be no contract of employment in the periods when the guides were not working.

The absence of an employment relationship between assignments makes it very difficult for casual workers to enforce employment rights that require continuous service, such as the right to claim unfair dismissal. There is more information about this in Chapter 10 Unfair dismissal: what is continuous employment?