Okuoimose v City Facilities Management (UK) Ltd - Illegal employment: the right to work in the UK, and evidence of that fact  EAT
A stamp in a passport may be evidence of the right to stay and work in the UK, but it does not create that right in itself. If the right exists (for example due to being a family member of an EEA national) then the expiry of a passport stamp will not alter that fact, and will not make continued employment illegal.
Nigerian Mrs Okuoimose worked for City Facilities Management (CFM) as a cleaner at ASDA. Her passport gave her “right of residence in the UK as a family member of an EEA national (Mr Okuoimose), who is resident in the UK in the exercise of a Treaty right, is hereby given, until 8 July 2010.” (the "residence card"). On 8 July 2010 she was suspended without pay, subject to proving entitlement to work. Mrs Okuoimose said that she had applied to extend her permit, but UKBA told CFM that it had no record of this. On 20 August CFM dismissed Mrs Okuiomose on the grounds that it would be illegal to continue to employ her.