The ‘illegality principle’ prevents a court from aiding a claimant who has based their claim on an immoral or illegal act, meaning that a tribunal or court will generally not enforce an illegal contract.
An employer of an individual working under an illegal contract can raise a defence against any employment claims the individual may bring against them. This is what is known as the ‘illegality
defence’, the basis of which is that the contract is illegal and therefore void, so the claim should not succeed.
A common example of an individual working under an ‘illegal contract’ would be an employee who is working in the UK despite not having the right to – i.e. working illegally, in breach of immigration laws.
In recent years, tribunals and civil courts have been reluctant to allow an employer to use the illegality defence to block vulnerable migrant workers’ employment tribunal claims.
An interesting Court of Appeal decision has further illustrated this. The case of Okedina v Chikale, has shown that an employer cannot always automatically rely on a breach of immigration rules to argue that an employment contract is unenforceable. The matter concerned contractual claims (including unfair dismissal) brought by a Malawian national whose leave to remain (and right to work) in the UK had expired two years before the time she was summarily dismissed.