A "worker" means a worker within the meaning of EU law. The term has been exhaustively considered by the European Court of Justice. There are three essential criteria which determine whether a person is a worker:
(i) the person must perform services of some economic value. The activity must be real and genuine, to the exclusion of activity on such a small scale as to be regarded as purely marginal and ancillary;
(ii) the performance of such services must be for and under the direction of another person. Any activity performed outside a relationship of subordination must be classified as an activity pursued in a self employed capacity;
(iii) the person concerned must receive remuneration. Neither the origin of the funds from which the remuneration is paid nor the limited amount of that remuneration can have any consequences with regard to whether or not the person is a worker. This is true even if the worker relies upon welfare benefits to supplement his income; There has been recent confirmation of this principle in Vatsouras and Koupatantze v Arbeitgemeinschaft (ARGE) Nurnberg 900, C-22/08 and C-23/08.
In Elmi v SSWP  EWCA Civ 1403, the appellant was an EEA national who had become involuntarily unemployed and then claimed income support. She ticked the box on the application form stating that she was looking for work. The Court of Appeal held that she had registered with the employment office as a jobseeker, even though she was in receipt of income support and not jobseeker's allowance, and had therefore retained her worker status.
The fact that the employment is of short duration cannot, of itself, exclude the employee from being a worker: see Barry v Southwark LBC  EWCA Civ 440;  HLR 30 (steward at Wimbledon). Even working just ten or twelve hours per week does not necessarily preclude a person from being a worker.
A person who ceases to be employed does not lose "worker" status instantly, I(EEA) 2006 reg.6(2). A person who is no longer working shall not cease to be treated as a worker if:
• he is temporarily unable to work as the result of an illness or accident;
• he is in duly recorded involuntary unemployment after having been employed in the UK, provided that he has registered as a jobseeker with the relevant employment office and he was employed for one year or more before becoming unemployed;
he has been unemployed for no more than six months;
he can provide evidence that he is seeking employment in the UK and has a genuine chance of being engaged;
he is involuntarily unemployed and has embarked on vocational training;
he has voluntarily ceased working and embarked on vocational training that is related to his previous employment.
In this context, "temporary" means not permanent. In Secretary of State for the Home Department v FB  UKUT 447 (IAC), at -, it was held that for the purposes of regulation 6(2)(a), a person whose inability to work as a result of illness or accident is not permanent, is temporarily unable to work.
In Secretary of State for Work and Pensions v JS (IS)  UKUT 131 (AAC), it was held that an EU citizen who was no longer employed or on maternity leave from work and who was pregnant, did not retain her status as a worker and therefore had no right to reside in the UK.
This is to be contrasted with the position of a woman on maternity leave. In Secretary of State for Work and Pensions v Maria Dias  EWCA Civ 807, the Secretary of State agreed that Ms Dias retained her worker status whilst on maternity leave and the Court of Appeal proceeded on the basis this was correct: see . To succeed with such cases, the woman should be on a formal period of maternity leave from her employment, or on statutory maternity pay or maternity allowance if self-employed.