Does knowledge that a contract of employment is not temporary (contrary to immigration law) render it void from inception, thereby allowing an employer to rely upon the defence of illegality?

No, held the EAT in Okedina v Chikale.

The Claimant was brought to the UK as a domestic worker but her immigration status meant that after six months she was working illegally. After two years she brought claims including unfair dismissal. The Respondent argued that the employment contract was illegal, namely in breach of immigration law. The tribunal rejected that argument, finding that the Claimant did not have knowledge of the illegality (third category of illegality under Hall v Woolston Hall Leisure Ltd).

The Respondent appealed on the basis that the contract to work in the UK was unlawful when it was formed (second category of illegality under Hall), as neither party believed the work to be temporary. It was submitted that it was void from inception.

The EAT rejected the appeal. The contract was terminable on six weeks’ notice and as such was not in breach of immigration law. Further, the legislation relied upon did not invalidate the contract, as even if it provided for a potential criminal offence, it said nothing about the validity of the contract entered into by the employer. Lastly, the EAT noted that even when considering the broader purpose of legislation (in prohibiting illegal conduct), there would have to be consideration of public policy and at that point the case would likely fall within the third category of Hall.