Well, it's how CJEU (formerly ECJ) interprets term "worker". So far it referred to the activity being GENUINE AND EFFECTIVE (Levin Case 53/81 and Kempf Case 139/85
http://eur-lex.europa.eu/LexUriServ/Lex ... 39:EN:HTML
13 THE COURT HAS CONSISTENTLY HELD THAT FREEDOM OF MOVEMENT FOR WORKERS FORMS ONE OF THE FOUNDATIONS OF THE COMMUNITY . THE PROVISIONS LAYING DOWN THAT FUNDAMENTAL FREEDOM AND , MORE PARTICULARLY ,
THE TERMS ' WORKER ' AND ' ACTIVITY AS AN EMPLOYED PERSON ' DEFINING THE SPHERE OF APPLICATION OF THOSE FREEDOMS MUST BE GIVEN A BROAD INTERPRETATION IN THAT REGARD , WHEREAS EXCEPTIONS TO AND DEROGATIONS FROM THE PRINCIPLE OF FREEDOM OF MOVEMENT FOR WORKERS MUST BE INTERPRETED STRICTLY .
14 IT FOLLOWS THAT THE RULES ON THIS TOPIC MUST BE INTERPRETED AS MEANING
THAT A PERSON IN EFFECTIVE AND GENUINE PART-TIME EMPLOYMENT CANNOT BE EXCLUDED FROM THEIR SPHERE OF APPLICATION MERELY BECAUSE THE REMUNERATION HE DERIVES FROM IT IS BELOW THE LEVEL OF THE MINIMUM MEANS OF SUBSISTENCE AND HE SEEKS TO SUPPLEMENT IT BY OTHER LAWFUL MEANS OF SUBSISTENCE . IN THAT REGARD IT IS IRRELEVANT WHETHER THOSE SUPPLEMENTARY MEANS OF SUBSISTENCE ARE DERIVED FROM PROPERTY OR FROM THE EMPLOYMENT OF A MEMBER OF HIS FAMILY , AS WAS THE CASE IN LEVIN , OR WHETHER , AS IN THIS INSTANCE , THEY ARE OBTAINED FROM FINANCIAL ASSISTANCE DRAWN FROM THE PUBLIC FUNDS OF THE MEMBER STATE IN WHICH HE RESIDES , PROVIDED THAT THE EFFECTIVE AND GENUINE NATURE OF HIS WORK IS ESTABLISHED .
http://www.acsnavigator.co.uk/acsbenefi ... e_Work.htm
The term ‘worker’ is a European concept and is interpreted in a flexible way. A person may be a worker whether in full or part-time work. From case law, the following general principles apply in the interpretation of ‘worker’ as it is to be defined in the European context:
* work must be ‘effective and genuine work’ and not merely ‘marginal and ancillary’ (Levin Case 53/81 and Kempf Case 139/85);
* it includes part-time work even if ‘topped up’ with benefits (Kempf);
* there must be an employment relationship where the worker accepts directions from another and the work is carried out in return for remuneration. (Lawrie-Blum Case 66/85);
* pay can be by payment in kind (Steymann [1988] ECR 6159).